Misinformation abounds on this subject. Here is the straight message.
JWS 3309 is the correct fluid for AW 5 speed automatics for Volvo. The Volvo dealers stocks this fluid. It's NOT synthetic. It's real expensive from the dealer ($18 a quart). It's made by Mobil and is Mobil 3309.
Second option is to get a case of 12 from a Mobil dealer of Mobil 3309. It's about $46.50 a case.
Do three drain and fills. Find the little yellow dipstick, open hood right side 2/3rd of the way down, move a coolant fluid hose out of the way, you will find it. Fill from there. The plug is obviously underneath like changing your own oil. Uses an allen wrench to loosen and remove it. 3 quarts will flow out, (could be hot and fast watch out). Find a long funnel and snake to the dipstick tube. Fill 3 quarts of 3309 and put yellow dipstick back in.
Do three times total to get virtually new fluid in there. The other 6 quarts are in the torque converter and that's why you have to drive around the block to mix it up every drain.
Call a Mobil distributor like the one below.