How to add passcode to Android Safe Mode?

*I selected this sub-forum because my Samsung phone, the Galaxy J7, does not have its own sub-forum.

Hello,

I've been attempting to find the easiest solution to add a passcode to safe mode on Android 7. I don't want the passcode to be the same one to unlock the Android phone.

The only solutions I've come across so far are paid subscriptions for mobile device management software. These kinds of programs are able to lock safe mode with a standalone passcode.

I'm wondering if there is a simpler, and possibly free, way of setting a passcode on safe mode?

I appreciate any help I can get.

Luke