Reset-wipe- when PW not known

Here is how to erase and re-install: Erase your Mac and reset it to factory settings - Apple Support

Various Macs have differing sequences.

Guess: Need to use Show All Disks, and reset the whole device and not a partition (2s5) as appears to be the case here.

Here is what the seller needs to do: What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

That sequence can be done remotely.

If Activation Lock is set, then contact the seller and request its release, or a refund. We can’t help bypass that, and — absent sufficiently-convincing proof of ownership — Apple won’t.

You might have a brick here, if ownership of this Mac was not properly relinquished by its previous owner.

Here re the instructions for an older intel Mac:

Links from that image are included below:

• Use Disk Utility to erase an Intel-based Mac - Apple Support
• How to reinstall macOS - Apple Support
• Reset NVRAM on your Mac - Apple Support