update from https://gist.github.com/adrianhall/f330a10451f05a529680f32978dddb64 to run in AppSync queries console

AWSAppSync2.yaml

---
Description: AWS AppSync Notes API

Parameters:
  APIName:
    Type: String
    Description: Name of the API - used to generate unique names for resources
    MinLength: 3
    MaxLength: 20
    AllowedPattern: '^[a-zA-Z][a-zA-Z0-9_]*$'

Resources:
  SNSRole:
    Type: AWS::IAM::Role
    Description: "An IAM Role to allow Cognito to send SNS messages"
    Properties:
      RoleName: !Sub ${APIName}-cognito-sns-role
      ManagedPolicyArns:
        - Ref: CognitoSNSPolicy
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sts:AssumeRole
            Principal:
              Service:
                - cognito-idp.amazonaws.com
    DependsOn:
      - CognitoSNSPolicy

  CognitoSNSPolicy:
    Type: AWS::IAM::ManagedPolicy
    Properties:
      Description: Managed policy to allow Amazon Cognito to access SNS
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action: sns:publish
            Resource: "*"

  DynamoDBRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Sub ${APIName}-appsync-dynamodb-role
      ManagedPolicyArns:
        - Ref: AppSyncDynamoDBPolicy
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sts:AssumeRole
            Principal:
              Service:
                - appsync.amazonaws.com
    DependsOn:
      - AppSyncDynamoDBPolicy

  AppSyncDynamoDBPolicy:
    Type: AWS::IAM::ManagedPolicy
    Properties:
      Description: Managed policy to allow AWS AppSync to access the tables created by this template.
      Path: /appsync/
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - dynamodb:GetItem
              - dynamodb:PutItem
              - dynamodb:DeleteItem
              - dynamodb:UpdateItem
              - dynamodb:Query
              - dynamodb:Scan
              - dynamodb:BatchGetItem
              - dynamodb:BatchWriteItem
            Resource: !Join [ "", [ !GetAtt DynamoDBNotesTable.Arn, "*" ] ]

  UserPool:
    Type: "AWS::Cognito::UserPool"
    Description: "A Cognito user pool for authenticating users"
    Properties:
      UserPoolName: !Sub ${APIName}-user-pool
      MfaConfiguration: "OPTIONAL"
      SmsConfiguration:
        ExternalId: !Sub ${APIName}-external
        SnsCallerArn: !GetAtt SNSRole.Arn
      Schema:
        - Name: email
          AttributeDataType: String
          Mutable: true
          Required: false

  UserPoolClient:
    Type: "AWS::Cognito::UserPoolClient"
    Description: "App Client used by AWS AppSync"
    Properties:
      ClientName: !Sub ${APIName}-appsync-client
      GenerateSecret: false
      UserPoolId: !Ref UserPool
      ExplicitAuthFlows: [ "ADMIN_NO_SRP_AUTH", "USER_PASSWORD_AUTH" ]

  DynamoDBNotesTable:
    Type: "AWS::DynamoDB::Table"
    Description: "Data store for AWS AppSync Notes Type"
    Properties:
      TableName: !Sub ${APIName}-notes-table
      AttributeDefinitions:
        - AttributeName: "NoteId"
          AttributeType: "S"
        - AttributeName: "UserId"
          AttributeType: "S"
      KeySchema:
        - AttributeName: "NoteId"
          KeyType: "HASH"
        - AttributeName: "UserId"
          KeyType: "RANGE"
      GlobalSecondaryIndexes:
        - IndexName: "UserIndex"
          KeySchema:
            - AttributeName: "UserId"
              KeyType: "HASH"
          Projection:
            ProjectionType: "ALL"
          ProvisionedThroughput:
            ReadCapacityUnits: 5
            WriteCapacityUnits: 5

      ProvisionedThroughput:
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5

  AppSyncApi:
    Type: "AWS::AppSync::GraphQLApi"
    Description: "The GraphQL API for the Notes App"
    Properties:
      AuthenticationType: "AMAZON_COGNITO_USER_POOLS"
      Name: !Sub ${APIName}
      UserPoolConfig:
        UserPoolId: !Ref UserPool
        AwsRegion: !Sub ${AWS::Region}
        DefaultAction: "ALLOW"

  AppSyncSchema:
    Type: "AWS::AppSync::GraphQLSchema"
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      Definition: |
        type Note {
          NoteId: ID!
          title: String
          content: String
        }
        type PaginatedNotes {
          notes: [Note!]!
          nextToken: String
        }
        type Query {
          allNotes(limit: Int, nextToken: String): PaginatedNotes!
          getNote(NoteId: ID!): Note
        }
        type Mutation {
          saveNote(NoteId: ID!, title: String!, content: String!): Note
          deleteNote(NoteId: ID!): Note
        }
        type Schema {
          query: Query
          mutation: Mutation
        }

  AppSyncNotesTableDataSource:
    Type: "AWS::AppSync::DataSource"
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      Name: !Sub ${APIName}_notes_table
      Description: "The Notes Table AppSync Data Source"
      Type: AMAZON_DYNAMODB
      ServiceRoleArn: !GetAtt DynamoDBRole.Arn
      DynamoDBConfig:
        TableName: !Ref DynamoDBNotesTable
        AwsRegion: !Sub ${AWS::Region}

  AppSyncAllNotesQueryResolver:
    Type: "AWS::AppSync::Resolver"
    DependsOn: AppSyncSchema
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      TypeName: Query
      FieldName: allNotes
      DataSourceName: !GetAtt AppSyncNotesTableDataSource.Name
      RequestMappingTemplate: |
        {
          "version": "2017-02-28",
          "operation": "Query",
          "index": "UserIndex",
          "query": {
            "expression": "UserId = :id",
            "expressionValues": {
              ":id": $util.dynamodb.toDynamoDBJson($ctx.identity.sub)
            }
          }
        },
        "limit": $util.defaultIfNull(${ctx.args.limit}, 20),
        "nextToken": $util.toJson(${ctx.args.nextToken})
      ResponseMappingTemplate: |
        {
          "notes": $util.toJson($ctx.result.items),
          "nextToken": $util.toJson(${ctx.args.nextToken})
        }

  AppSyncGetNoteQueryResolver:
    Type: "AWS::AppSync::Resolver"
    DependsOn: AppSyncSchema
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      TypeName: Query
      FieldName: getNote
      DataSourceName: !GetAtt AppSyncNotesTableDataSource.Name
      RequestMappingTemplate: |
        {
          "version": "2017-02-28",
          "operation": "GetItem",
          "key": {
            "NoteId": $util.dynamodb.toDynamoDBJson($ctx.args.NoteId),
            "UserId": $util.dynamodb.toDynamoDBJson($ctx.identity.sub)
          }
        }
      ResponseMappingTemplate: "$util.toJson($ctx.result)"

  AppSyncSaveNoteMutationResolver:
    Type: "AWS::AppSync::Resolver"
    DependsOn: AppSyncSchema
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      TypeName: Mutation
      FieldName: saveNote
      DataSourceName: !GetAtt AppSyncNotesTableDataSource.Name
      RequestMappingTemplate: |
        {
          "version": "2017-02-28",
          "operation": "PutItem",
          "key": {
            "NoteId": $util.dynamodb.toDynamoDBJson($ctx.args.NoteId),
            "UserId": $util.dynamodb.toDynamoDBJson($ctx.identity.sub)
          },
          "attributeValues": {
            "title": $util.dynamodb.toDynamoDBJson($ctx.args.title),
            "content": $util.dynamodb.toDynamoDBJson($ctx.args.content)
          }
        }
      ResponseMappingTemplate: "$util.toJson($ctx.result)"

  AppSyncDeleteNoteMutationResolver:
    Type: "AWS::AppSync::Resolver"
    DependsOn: AppSyncSchema
    Properties:
      ApiId: !GetAtt AppSyncApi.ApiId
      TypeName: Mutation
      FieldName: deleteNote
      DataSourceName: !GetAtt AppSyncNotesTableDataSource.Name
      RequestMappingTemplate: |
        {
          "version": "2017-02-28",
          "operation": "DeleteItem",
          "key": {
            "NoteId": $util.dynamodb.toDynamoDBJson($ctx.args.NoteId),
            "UserId": $util.dynamodb.toDynamoDBJson($ctx.identity.sub)
          }
        }
      ResponseMappingTemplate: "$util.toJson($ctx.result)"

Outputs:
  CognitoUserPoolId:
    Description: The Pool ID of the Cognito User Pool
    Value: !Ref UserPool
  CognitoUserPoolClientId:
    Description: The Client ID for AWS AppSync Auth
    Value: !Ref UserPoolClient
  DynamoDBNotesTableName:
    Description: The name of the DynamoDB Table
    Value: !Ref DynamoDBNotesTable
  GraphQLApiEndpoint:
    Description: The URL to the GraphQL Endpoint
    Value: !GetAtt AppSyncApi.GraphQLUrl
  GraphQLApiId:
    Description: The API ID of the GraphQL API
    Value: !GetAtt AppSyncApi.ApiId