AWS Cloudformation Resource Method. No match for output mapping and no default output mapping configured.

The issue might be related to the setup of your CloudFormation template for the API Gateway resource method. Specifically, it seems that there might be a syntax issue with your AuthPOSTMethod resource. Here's how you can address the issue:

Check IntegrationHttpMethod: Ensure that the IntegrationHttpMethod property is properly aligned under the Properties section.

Indentation and Formatting: Double-check the indentation and formatting of your CloudFormation YAML. Proper indentation is crucial to ensure that properties are correctly associated with their respective resources.

Response Configuration: Verify your response configuration, including the output mappings, response templates, and response models.

Based on the code you provided, it appears there might be a minor formatting error with the IntegrationHttpMethod property. Here's a corrected version of your CloudFormation snippet:

AuthPOSTMethod:
  Type: AWS::ApiGateway::Method
  DeletionPolicy: Delete
  Properties:
    AuthorizationType: NONE 
    HttpMethod: GET 
    ResourceId: !ImportValue ExAuthResources
    RestApiId: !ImportValue ExPortedAPI
    Integration:
      IntegrationHttpMethod: GET
      Type: MOCK 
      RequestTemplates:
        application/json: '{"statusCode": 200}'
    RequestModels:
      application/json: 'Empty'