Rainbow Six Siege not launching

So last week I got Rainbow Six Siege (a friend gave me his Ubisoft account with the game purchased on it for free as he doesn’t play the game) and when I got it and clicked play it took me directly to steam where my personal account was logged in and the game files downloaded from steam. The game ran perfectly fine for a few days. However, I did not play for 2 days as I was busy and today when I ran the game it wasn’t launching.

Whenever I launched the game from the Ubisoft launcher it took me to a rainbow six siege page on steam and asked me to buy the game. Also apparently the game was free on Steam for a trial last week, maybe that messed up something? What should I do to fix the issue? Many thanks in advance