Set CORS headers for OPTIONS method with Serverless Functions

When calling a Function via HTTP with the OPTIONS method, my Function’s code is not executed. I need to change the Access-Control-Allow-Credentials and Access-Control-Allow-Origin headers for any OPTIONS request.

It seems like the response for an OPTIONS request is static and does not invoke the Function at all. Other methods work.

These Functions are not part of an App.

I have tried with both web: true and web: raw but neither worked.

project.yml:

packages:
  - name: mypackage
    shared: false
    environment: {}
    parameters: {}
    annotations: {}
    functions:
      - name: sessionCreate
        binary: false
        main: ""
        runtime: nodejs:18
        web: raw
        websecure: false
        parameters: {}
        annotations: {}
        limits: {}