Does Github API support X-HTTP-Method-Override?

I am trying to use to accept repository invitations.

It says to send a Patch, but in my case I can only send a POST (my client framework can’t support sending PATCH).  I have tried to use a POST method and then set X-HTTP-Method-Override to PATCH but that didn’t seem to work.  Does anyone know if github api supports X-HTTP-Method-Override?

According to this: I should be able to send a POST instead of a patch, but that doesn’t seem to work for accepting a repo invitation.  But perhaps I’m not sending my POST right.  Should it have a body or just a URL only? 

I’ve tried to send a POST with a json body like this 

curl -u user:token -d '{"invitation\_id":"26497928"}' -H "Content-Type: application/json" -X POST [\_invitations](  

But that returns a 404

"message": "Not Found",  
"documentation\_url": "[]("  

Then when I tried a POST with just URL only, no data

curl -u user:token -X POST [\_invitations/26497928](

It doesn’t work either.  I hope there is a Gandolf out there has the knows how to say friend in Elvish to get me through this door.