You can try using the instructions in the following article:
How To Fully Erase A Mac Using Recovery Assistant - Apple Community
If that does not work, then you will likely need to perform a DFU Firmware Restore which requires access to another Mac currently running macOS 26.x Tahoe or macOS 15.7.3+ Sequoia.
Your company should be very careful providing full access to a Mac to other people (even to company employees). It is generally a good idea to implement some sort of management system & restrictions so the business can retain ownership & control of the Mac, otherwise it can be a difficult process to reacquire ownership of a locked Mac. Your company/employer should look into an MDM solution (Mobile Device Management) so you can prevent a user from assigning their AppleID to the full computer & locking your company out of the device. Plus it makes things much easier to fix if a device does become locked.....and a device will become locked sooner or later.
Until an MDM or management solution can be implemented, the company should make sure to assign an AppleID to each device to prevent any individual user from doing so and locking the owner (the company) out of their own devices. This option is not ideal, but better than nothing until a proper MDM can be implemented.
The company doesn't have to restrict everything, but it should restrict an individual user from being able to assign their AppleID to the device & locking the company out of a company device. See the following Apple article for some details:
Choose a mobile device management solution - Apple Support
