Is it possible to send a link that is not from YouTube?
I made an amazing video for the competition, but YouTube is blocking it because of the copyright of the background music.
Or is it possible to replace the video even after the competition deadline?
Also make sure that you have the proper legal rights for anything you are submitting. If YouTube is blocking your video due to Copyright issues, it is very likely that your submission will get disqualified from the competition.
According to the instructional video, it can be read that it can be uploaded to Youtube and further to another social network (hashtags are also specified when uploading to social networks)
Therefore, we recommend that you upload it to Youtube first (Googler replied in another topic that it is okay to make it private).