Secure Access to REST-API from Web? (Siri Shortcuts)


Is there a way to get secure access to the rest-api through mobile net? I would like to call the api with siri shortcuts.
Acually i get access to my openhab server through the local network or a vpn connection. but the vpn connection is only established, if my mobile phone is connected to another wifi-network than my home wifi-net.

Would be happy about some ideas to this topic and, of course, i wish you all a merry christmas!

Yours, Alex