Calling a SSL endpoint from An Azure Function

It looks like when you create a function app now by default TLS 2.0 is selected which Invoke-RestMethod doesn't like. If you go into platform options - SSL you can change it back to 1.0 or add

“[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]'Ssl3,Tls,Tls11,Tls12'”

to your client PS script.