If you are looking for a "free update" on how to handle T2-equipped Macs (models from 2018–2020), here is the current state of the landscape. What is the T2 Chip?
Understanding MacBook T2 Bypass: Methods, Security, and Current Updates macbook t2 bypass free upd
If your MacBook is locked at the BIOS/Firmware level (a black screen with a padlock), the "free" update is a bit simpler: If you are looking for a "free update"