Company iPhones from former employees locked to owner

If the device is enrolled in Apple School/Business Manager, you can remove the Activation Lock via the ASM/ABM portal.

If the device is not enrolled in ASM/ABM, but is enrolled in Mobile Device Management, you should be able to remove the Activation Lock via MDM.

If neither applies, you will need the original proof of purchase and contact Apple Support for assistance.

If you do not have the original proof of purchase, you will need the former employees to assist in removing Activation Lock.

If the former employees cannot or will not assist, you have a paperweight.

If you do not have Apple Business/School Manager set up for your org, you should absolutely do so. It's 100% free and has lots of useful tools.

If you do not have an MDM platform, you should strongly consider adding one.

If these phones were managed by your business, your IT department may be able to reset them. I could be wrong – but I think that with MDM systems, the phones might be locked to the business.

If they were not, contact your former employees and ask for their help in removing Activation Lock. Or submit Activation Lock support requests to Apple (proof of ownership required), and hope that Apple grants them.

How to remove Activation Lock - Apple Support

https://al-support.apple.com/#/be/agreement

There is no magic bypass for Activation Lock, so if you cannot clear it in one of these ways, these phones wll essentially be "bricks."