Organic maps imports all business locations from google maps Afaik. Just import your own kml file to drop the pins. Even supports multiple different location markers. Live position tracking included and navigation if you ever want to return. No self hosting required at all.
Funnily enough I have written a system to do exactly that as a bachelor’s theses for IT security.
Places client certificates and a client inside the initrd and requests securely the key to unlock.
The sever waits for you to approve the request before providing the key. The key is only held in memory during boot.
I had a version that included for a hidden key provider and planned for a version that included time based auto unlocks etc.
I was planning to package that and release it as open source.
Still might do that.