Guide
Whether you play in person or online, here is exactly how to capture your session audio and upload it for transcription.
Check the recording folder before converting anything. Zoom writes an audio_only.m4a alongside the MP4 for local recordings, and Craig on Discord gives you audio only in the first place. If a matching audio file is already sitting there, you are done. Upload that.
Audacity can import most video files with the FFmpeg add-on installed, then File › Export › Export as MP3. It is the slower route, but if Audacity is already on your machine for editing out the pizza break, you may as well use it for both.
Open the video in QuickTime Player, then File › Export As › Audio Only. It produces an .m4a in one step with nothing to install. It only handles formats QuickTime can already open, so MKV files from OBS need VLC instead.
Scrivorn accepts audio files up to six hours long:
Video files are not accepted, see I have a video file for how to pull the audio out of an MP4 in a couple of minutes. Sessions longer than six hours should be split in two and uploaded as two sessions; Audacity does this for free.