How to call default API endpoint in custom plugin?

Ahhh I see it after checking the same as yours. The normal Api call when used is throwing back to the login screen.

Is there any specific requirement of yours for which you are calling the Normal src/api/data/routes/data.ts? If not, then give it a try by following the above solution which I gave you (Add your Route & Controller with code) under your plugin folder and check if that works okay for you.