Internal Error Code 131 - Creating Webook



Cross-posting from Internal Error Code : 131 - WebHook -RestAPI since that topic is marked as solved

When attempting to create a new webhook I am getting the 131 internal error code. I see that Twitter is pinging my webhook and the response is the correct one, I know this since it was validated in the past, the latency is low, etc.
I’ve tried everything I can think of but cannot make it work. The request I’m using is
twurl -X POST /1.1/account_activity/webhooks.json?url=https://mydomain/webhook
but I’ve also tried other options, sending the url as post data, json, url encoded, etc.

Please help! I’ve been stuck here for more than a week.