I bought a second-hand 2019 MacBook Pro that was not working and had the board repaired at a shop. I had erased the drive as I would on a Windows PC six months ago. Now, the Mac won’t boot into the standard recovery mode. It only starts from online recovery. I tried booting it from an external drive, but it didn’t work. This Mac also has an activation lock, and I have no account or password.
To boot from an external drive on a T2 Mac, you must modify the system security settings to allow booting from external media before erasing the internal hard drive.
Once you erase the hard drive, all references to the admin user accounts are removed. You won’t be able to authenticate and modify system security settings afterward.
You should ask the seller for the Apple ID and password to activate the Mac. Otherwise, you won’t be able to use it.
Activation Lock on a Mac is a security feature designed to prevent unauthorized use of the device. If someone tries to reset a Mac that has Activation Lock enabled, they won’t be able to use it without entering the credentials of the Apple ID that was originally used to set it up.