Question on Live Tik Toks

Hello BHW peeps,
wanted to ask if anyone is knowledgeable in tik tok lives, I was on tik tok and saw a livestream which was clearly not a livestream, but lookd great it was a livestream of two astronauts working on a satellite above earth.
Clearly this was not their livestream video, so question is how can you livestream a pre-recorded video on tik tok?

something something 'restream'. Now if I can get that as -aas

gotcha think its called OBS