Ecu or amp under driver seat

I saw a little object that looks like a ecu or amp under my driver seat. I know that the ecu is in the pass side kick panel. My truck is 1990 extended cab, not sure what package it has.

Anti-lock brake controller.

Thank you

Can I remove it or do I need?

I wouldn't remove any safety-related stuff.

Thanks.

my 91 has that same box but i dont have abs

If you have a sensor connection at the rear differential, you have ABS.

Ill have to check into that, i just have the base model so idk

Where exactly would sensor be at & How would i know which model i have truck dosnt have the side stickers?