My '98 V70R AWD was a 4 speed auto for which Volvo recommended (at the time of production) Dexron IIE ATF - I flushed it through with Dexron III which is fully compatible and replaces Dexron IIE.
If you have a look at my website
https://www.duckfieldengineering.com/850R/ and click on the 'Deciphering VIN' link you'll see which number to check in your VIN to see which gearbox is fitted. I reckon it'll be an AW42 like my old one, so the gearbox ID number should be an '8'.
If so, you'll need Dexron III. Pic below shows how dirty my old ATF fluid was!
NB This is my 'development' site, the live one will be at
https://www.850R.co.uk shortly... (just need to bounce someone who has cyber-squatted on my site URL!)