How to add AWS Amplify function typescript

.vscode_settings.json

{
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "source.organizeImports": true
  },
  "typescript.tsdk": "node_modules\\typescript\\lib",
  "files.autoSave": "afterDelay",
  "search.exclude": {
    "**/node_modules": true,
    "**/.vscode": true,
    "**/build": true
  },
  "git.autofetch": true,
  "javascript.format.enable": false,
  "typescript.implementationsCodeLens.enabled": true,
  "editor.trimAutoWhitespace": true,
  "files.encoding": "utf8",
  "files.trimFinalNewlines": true,
  "files.trimTrailingWhitespace": true,
  "eslint.validate": ["typescript"],
  "eslint.workingDirectories": [{ "pattern": "amplify/backend/function/*/ts" }],
  "[typescript]": {
    "editor.formatOnSave": false,
    "editor.codeActionsOnSave": {
      "source.fixAll.eslint": true
    }
  }
}

index.ts

import { Callback, Context, Handler } from 'aws-lambda';

interface TriggerEvent {
  key1: string;
  key2: string;
  key3: string;
}

export const handler: Handler<TriggerEvent, string> = (event: TriggerEvent, context: Context, callback: Callback<string>) => {
  const concatKey = `${event.key1} ${event.key2} ${event.key3}`;
  callback(null, concatKey);
};

tsconfig.json

{
  "compilerOptions": {
    "declaration": false,
    "target": "ES2017",
    "module": "commonjs",
    "moduleResolution": "node",
    "rootDir": ".",
    "lib": ["es2017"],
    "typeRoots": ["node_modules/@types"],
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "noImplicitAny": true,
    "sourceMap": false,
    "strict": true,
    "baseUrl": ".",
    "outDir": "../src"
  },
  "include": ["./**/*"],
  "exclude": ["node_modules"]
}