I want to speedrun the category "Any%".I'm Chinese and I saw some Chinese use YouTube to submit their runs.So,must I submit my run on YouTube?

First of all you need to know that every game has its rules regarding videos so my reply may not apply on other boards.

Usually the rule is "to have the video on a permanent link on a public website for everyone to see". Twitch and YouTube are preferred simply because they're the most reliable, accesible and popular but as far as I know any website, as long as it meets the criteria, is allowed.

Some sketchy websites are discouraged because they are unreliable or may be unaccessible for other users.

Wait,I can't watch any video on YouTube.In my country,We can't watch any video on YouTube except use speeder.So...Can I...Submit video on...Bilibili?

As long as we can watch the video too it's fine

Allright.I will also submit it on YouTube(by other Chinese players)