azure function connecting to fly postgres


I am very new to fly so apologies for what might be a trivial question…

I have an azure function that needs to be able to write to a fly postgres db. from the fly docs I am guessing I need to use a vpn to achieve this but not sure how I can set up wireguard on azure and have a server-less function use the tunnel? Does it have to be wireguard, can we use any VPN?

Any help is most appreciated.