Apigee target endpoint showing the use of implicit GCP authentication

target-1.xml

<TargetEndpoint name="target-1">
  <PreFlow name="PreFlow">
    <Request>
        <Step>
          <Name>AM-Query</Name>
        </Step>
    </Request>
    <Response>
      <Step>
        <Name>AM-Clean-Response-Headers</Name>
      </Step>
    </Response>
  </PreFlow>

  <PostFlow name="PostFlow">
    <Request/>
    <Response>
    </Response>
  </PostFlow>

  <Flows/>

  <HTTPTargetConnection>

   <!-- tell Apigee to invoke this with a Google Access Token -->
   <!-- see https://cloud.google.com/apigee/docs/api-platform/security/google-auth/overview -->
    <Authentication>
      <GoogleAccessToken>
        <Scopes>
          <Scope>https://www.googleapis.com/auth/cloud-platform</Scope>
        </Scopes>
      </GoogleAccessToken>
    </Authentication>

    <SSLInfo>
      <Enabled>true</Enabled>
      <IgnoreValidationErrors>false</IgnoreValidationErrors>
    </SSLInfo>
    <Properties/>
    <!-- assemble the target path -->
    <URL>https://bigquery.googleapis.com/bigquery/v2/projects/{{= projectId}}/queries</URL>
  </HTTPTargetConnection>
</TargetEndpoint>