Ok so , first step is preparation , you can get meat , prime meat or kibble (argentavis needs stego kibble) then you need to make a trap and for that trap you wil meed 5 stone dinosaur door frames and 2 reinforced dinosaur doors then you need to find an argy which want to tame then lure it inside your trap ( there are tutorial vids on youtube for building the trap ) then just knock it out with the tranq arrows and then use the starve method i which you need to knockout the dino and then let it starve (feed it things that will increase its torpor while knocked so it doesnt wake up while youre tying to starve it) then after it has starved feed it the meat or prime meat or stego kibble

And congrats You got yourself an argy now craft a saddle and explore ( argys reduce weight of metal, crystal, and organic polymer when it carries the stuff itself ) hope this helped 😁