Cannot resolve variable... Missing region in config

I have a handful of small Lambda functions that I’m deploying with serverless in travis ci.

My configs look like this:

service: service-name
variablesResolutionMode: 20210326
provider:
  name: aws
  runtime: python3.6
  stage: prod
  region: us-east-1

  environment:
    CONSUMER_KEY: ${ssm:consumer_key}
    CONSUMER_SECRET: ${ssm:consumer_secret}
    TOKEN: ${ssm:token}
    TOKEN_SECRET: ${ssm:token_secret}
functions:
  hello:
    handler: function.handler
    events:
      - schedule: rate(1 day)

I’ve started getting these warnings:

 Serverless Error ----------------------------------------

 

  Cannot resolve serverless.yml: Variables resolution errored with:

    - Cannot resolve variable at "provider.environment.CONSUMER_KEY": Missing region in config,

    - Cannot resolve variable at "provider.environment.CONSUMER_SECRET": Missing region in config,

    - Cannot resolve variable at "provider.environment.TOKEN": Missing region in config,

    - Cannot resolve variable at "provider.environment.TOKEN_SECRET": Missing region in config

But I can’t figure out what that means. What region am I missing?