How can I Factory reset this MacBook Pro

Idk th Mac is a 2017 or earlier (does not meet requirements in step 2) use the instructions in What to do before you sell, give away, or trade in your Mac - Apple Support and skip step 2 and use the other steps instead.

If it is a recent Mac and meets the requirements in step 2 of those instructions then see: Erase your Mac and reset it to factory settings - Apple Support

Read and follow these instructions.

Erase your Mac and reset it to factory settings - Apple Support