Access to fetch at 'apigw.XXXX' from origin 'http://localhost:3002' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status

Hello,
I’m trying to connect to my Rest API (a lambda function + serverless), but I’m getting this cors error in my front web app side:

Access to fetch at 'https://apigw.xxx from origin ‘http://localhost:3002’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: It does not have HTTP ok status.

I tried to add the cors config in my serverless.yml file like that:

functions:
  test:
    handler: "./src/functions/test/handler.main"
    events:
      - httpApi: 
          path: /test
          method: post
          cors:
            origin: '*'
            maxAge: 86400

I also added the headers to the returned response, but I’m still getting the same error.
Could anyone help me fix that?

Thanks