Clean install Monterey?

Hi, I need to install Monterey on my laptop (2015 MacBook Pro) but I've deleted the user accounts and the only one left - the admin account - I don't know the password (which in itself is strange, but still, I've never used the account, so ti could be anything). So I can't install Monterey without the password. Is there anyway to do a completely clean install - there's nothing left on the hard drive I need, so it can even be reformatted if required.

Thx.