Find my friends several iphones i have 2 iphones, the new for my business. I share my location on Find your friends with my family. When I‘m working, I often forgot my private iphone at home. So I would like to share my location with my firm iphone. I know, that I have to choose the iphone I want to share.

When I change on the app to my business iphone, will it send a message to my private iphone? And does it requiers an authorisation? Because when the private iphone is at home, I can‘t klick on the authorisation or the message. Thank you very much for your answers!
No, there's no authorisation required (besides being logged in on iCloud for Find your Friends on the other phone, which you already indicated is the case). There's no message sent to the phone that was previously the source of the location info.