How to resolve a target class who doesn't exist?

I following a tutorial on the web, I'm trying to do a auth api. With postman I'm trying the register url api and I have a persistant error. I'm trying some things but I don't understand what is the problem.

"Target class [App\Http\Controllers\Auth\RegisterController] does not exist.",

Postman

RegisterController

Api.php

Sorry I can't edit images, just links

via Chebli Mohamed