Add Upload tab

Hello!
Could you please tell me how to add a tab "Upload Files" for one of custom service? This tab exists on all libraries types (images, audio, video). I suppouse that is some controller's content which should be swiched to. I have tried to use some core js code for uploading but still no luck. Any help will be appreciated.

Start by inspecting how the existing image, audio, and video libraries add their tabs in the WordPress Add Media screen, then trace the custom-service integration point. Done means the custom service has an "Upload Files" tab and its uploads work reliably; the issue does not name a file or test to run.

Written by the indexing model from the issue text.