Some, if not most, services won't allow you to redirect cold to an IP address, they want some domain of sorts. There are alternatives, but I think "setup a proper dev environment" alone misses the point of what ngrok does.
The 'easiest' alternative I've tried before was to VPN into my Linux box to get a static internal IP, use a spare domain for the webhook then internally redirect the webhook traffic to my local machine. In the end I'm achieving what ngrok is doing (and none of it involves setting up a proper dev environment, cos I would already have one anyways), but I'd like to hear of better alternatives :)