for those who aren’t sure, beavers spawn in asgard! i found a few at lat-32.7 lon-26.3 (in asgard) also, if you are not sure on how to get to asgard, there is a small cave at lat- 39.8, lon-57.9 with portals to all 3 sections in. hope this helps!
I play on singleplayer, make sure the one you wanna tame is alone and doesn't have it's buddies arouns, bola it and knock it out usinf tranq arrows, took around 100 mejorberries and 20 narcotics. Time? Around 20-30 minutes.