Manually add devices to Apple Business Manager?
I work at a company that has 100+ iPhones that are not being managed through apple business manager. We need to get these into ABM so we can properly manage them. I have been researching how to add devices manually, however the option for adding devices by serial number, which I've seen in so many videos and guides, is not available in our portal.
I also read that you can use some configuration software on a MacBook to add them, but we don't have any MacBooks to do this.
How do I add these devices?