Yii2 Upload files & auth_key issue


I’m implementing a REST controller to upload files from a mobile app. I set the multipart content-type, the files to be sent and the auth_key because security reasons but the problem here is, with multipart/form-data, nothing is arriving, the bodyParam is empty, while, with rawBody, I get all.

How do I check the auth key inside checkAccess for normal posts and multipart posts?