How can you get free boosters?

[asd]

I know I got free boosters before, I just don't have any idea how I got them. I didn't buy them, because the only time I bought R6 credits was like 2 weeks ago when I bought 600. Never before that, but I have gotten 1 day boosters several times last year, and once I even had a 7 day booster... I just don't know how. Do you get that at the end of the season? Or do you get that as a reward for leveling up?

[Random]

Ubisoft gives boosters to everyone for extended downtimes.