Reference to a external swagger api definition

Serverless Framework
,
18

@salvadornava01 I’m trying this solution and encountered "The CloudFormation template is invalid: Template error: instance of Fn::GetAtt references undefined resource "

functions: 
  - myFunction: 
      handler: src/handler/updatePerson.handler

resources:
  Resources:
    Permission:
      Type: AWS::Lambda::Permission
      Properties:
       FunctionName:
      Fn::GetAtt:
        - myFunction
        - Arn
    Action: lambda:InvokeFunction
    Principal: apigateway.amazonaws.com