Slitherine

I have a problem: I bought combat mission black sea in 2017 on www.battlefront.com, but i dont have account number in slitherine.com. now I have the license keys of this game,how can i get the key on steam

I'm not sure what the connection is between Battlefront.com and Matrix/Slitherine, but there must be one because I found these two recent threads which may help you:

Combat Mission Black Sea - Out Now (See the first post which says "Anyone with a copy of the game purchased on Battlefront.com will also be able to redeem a Steam key HERE using their original game code.")

Redeeming Steam Keys (This thread has recent posts; see zakblood's latest post which also talks about "Anyone with a copy of the game purchased on Battlefront.com will also be able to redeem a Steam key using their original game code" with a link.)