unable to create api key from SecretsManager value

I have a Serverless stack deploying an API to AWS. I want to protect it using an API key stored in Secrets manager.


service: my-app
frameworkVersion: '2'

  name: aws
  runtime: nodejs12.x
    - name: apikey
      value: ${ssm:myapp-api-key}

The deployed API Gateway key should be the same as the SSM Secret, yet when I look in the console, the 2 values are different. What am I overlooking?

Qualifying question before trying to give you an answer.

Do you mean Secrets Manager or Parameter Store? Your code syntax would indicate you’re trying to pull from Parameter Store, but you said Secrets Manager in your question.