Callbacks and ngrok

[Mitchell Faircloth]

Hi,

I'm setting up a bot which will take commands from the chat and react appropriately. 
As I'm out of town, I don't have the ability to port forward a flask app on my local network which I would usually use as a callback URL. 

I'm attempting to use ngrok as a tunnel so I can develop on the go however I'm running into an issue where only my GET requests are coming through.
I've accessed my app through my browser, sent it posts with postman and an online API testing tool with no issues.

When I add the URL to my groupme bot, activating the bot will hit it with a get request and succeeds. 
However, when I send a message in my group chat, the post message I expect groupme to send doesn't even hit my ngrok app. 

Anyone seen anything similar?

Thanks!
Mitch