serverless-form-bucket-policy.yml

FrontendS3Policy:
  Type: AWS::S3::BucketPolicy
  Properties:
    Bucket: !Ref FrontendS3
    PolicyDocument:
      Version: "2012-10-17"
      Statement:
        - Effect: Allow
          Action:
            - s3:GetObject
          Principal:
            CanonicalUser: !GetAtt FrontendOAI.S3CanonicalUserId
          Resource: !Sub
            - arn:aws:s3:::${Bucket}/*
            - { Bucket: !Ref FrontendS3 }