How Does One Unlock A Company Issued iPhone 8?

I am the administrator for employee issued phones at my job. I had an employee was issued an iPhone 8 then soon after they left the company. The phone has a password assigned to it but the former employee says they don't remember what it is. It also has been assigned to an iCloud account but the former employee says they don't know what that is. Is there any other way to completely reset the phone without knowing the password or iCloud account so that I can reassign the phone to another employee? Thanks in advance.