exporting to youtube

Hi. I would like to know how youtube works: It can feature a variety of formats for a single video, as shown by youtube-dl "blablablabla" -F, including webm and mkv. The files I upload aren't of the best qualities sometimes... vintage recordings. So it is paramount that the files are uploaded as...

Does anyone else use Windowshare filmora to edit their youtube videos? Are you having any issues exporting to youtube? I had no issues with the trial version, but immediately after I bought it, I could not export. Anyone else? How did you resolve it if so?