amazon web services - How to set environment variables according to stage in cloud formation template

Question

The environment variables in the lambda handler has to be set via lambda handler according to the stage. The values for schema, endpoint are different for different stage. How can this be done via yml template. I am new to this, so don't know how this will be done.

Parameters:
   Stage: {Type: String, Default: ''}
Resources:
   LambdaHandler:
   Type: AWS::Serverless::Function
   Properties:
       Environment:
          Variables:
          ......
          ......

How to continue further?

Answer 1

I presume it would be:

Environment:
        Variables:
          your-key: !Ref Stage