Lambda@Edge function don't have trigger attached to them


I have a question about Lambda@Edge’s support in Serverless.

What I did so far is that I’ve created a simple function that is just adding a header to a request.

My serverless.yml file has this in it

    name: ${self:provider.stackName}-viewer-request
    handler: src/functions/viewer-request.handler
    memorySize: 128
    timeout: 4
      - cloudFront:
          eventType: viewer-request
          origin: s3://${self:custom.bucket}

So this is deploying as it should. It deploys lambda, it creates Cloudfront distribution, but it doesn’t attach a trigger to lambda I’ve created. Although when I try to add trigger manually I can use existing trigger (so it is created, just not attached to my lambda)
Any idea why this happens or what I did wrong?