Does the user have to enroll own devices in MDM to download custom apps with redemption code?

I know that I can get multiple redemption codes from Apple Business Manager, let users download custom apps using redemption codes, and there are region restrictions.

Does the user have to enroll own devices in MDM to download custom apps with redemption code?

Because users are not necessarily full-time employees of the company, they may also be short-term partners who use their own devices.