https://www.amazon.com/Archer-325-063-81DL-Chainsaw-Replaces-K3C-RP-81E/dp/B07N6G19ZX You will need to double check the numbers but looks like this should work.

What pitch, gauge and how many drive links?

Maybe this? Not sure if it's the right one, but I've had good luck with .325 Archer ripping chain in my MS250. Archer 20" .325-063-81DL Ripping Chainsaw Chain Replaces Stihl MS280 MS290 K3C-RP-81E https://www.amazon.com/dp/B07N6G19ZX/ref=cm_sw_r_apan_glt_fabc_AR0M29QPAF9GHRNHZAV4