Template format error: YAML not well-formed

Template format error: YAML not well-formed

我在该资源的最后一行得到 Template format error: YAML not well-formed,但不知道哪里出错了。

  LambdaPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt LambdaFunction.Arn
      Principal: apigateway.amazonaws.com
      SourceArn: !Join
        - ''
        - - !Sub 'arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:'
          - Fn::ImportValue:
            !Sub ${ParentStack}-api
          - '/*'

ImportValue 后面应该有一个标签:

  LambdaPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt LambdaFunction.Arn
      Principal: apigateway.amazonaws.com
      SourceArn: !Join
        - ''
        - - !Sub 'arn:aws:execute-api:${AWS::Region}:${AWS::AccountId}:'
          - Fn::ImportValue:
              !Sub ${ParentStack}-api
          - '/*'