There was a keybind, but there isn't anymore. To record now you can use the console(open by pressing ~) and type tpt.record(true). then when you're done recording you type tpt.record(false). It just outputs .ppm files so you'll need to use something like ffmpeg to make an actual gif of it.
Use OBS, if tpt.record doesnt work
@Videogamer555 (View Post)
If your platform is Windows 10 and you have registered on Xbox, then you may use Xbox Gamebar to record. If Gamebar doesn't recognize the application as a game, go to the settings using the Gamebar menu on the top center of the screen, and the setting "Remember this is a game" has to be checked. Gamebar is accessed by pressing Windows + G, unless the shortcut was disabled through settings. Otherwise, search "Gamebar" through Cortana. Let me know if there are further problems.
For Linux users -- I'm running Linux Mint, and the best thing I've ever used here is SimpleScreenRecorder. It has options for area and quality, highly configurable and easy to use. It puts out great Powder videos. One of my favorite features is being able to select a precise area to record. You can see exactly what you're going to get.