I just solved and issue with a discord webhook not liking .png files because they are too large.
I setup and action in StreamerBot, which saves an OBS screenshot, and I just put .JPG on the end of the filepath where the screenshot will be saved (same as recordings by default anyway)
So OBS wants to save a screenshot as a .png BUT StreamerBot sets the file type to .jpg when it sets the file name.
This creates jpg screenshots which are much smaller, so they can be posted as discord messages in my photography section without going over the 10mb per image limit discord has.