I am trying to send responses to inbound Google Business Messages via my web app. Unfortunately the Google documentation doesn't include PHP examples, nor can I find any reference to PHP helper libraries for business messaging. I'm more than happy to work with PHP curl but...
This line in Google's cURL example defeats me...
-H "$(oauth2l header --json ./service_account_key.json businessmessages)"
Is there any way to translate this to PHP cURL?
I haven't found a cURL-to-PHP auto-translator that is willing to deal with it either.
I believe it is asking the target server to execute some command, but how do I get PHP to do that?