Pawn Promotion:
Any Pawn which attains the first rank of an
active opponent territory may be promoted to either a Queen or to any other piece that player previously lost through capture. The piece to which the pawn is promoted replaces the pawn at the location of promotion. A player may possess no more than two Queens at any point, and no player may have more than three Bishops, three Knights, and two Rooks.
This image illustrates all the spaces at which Blue may promote a pawn:

Any pawn located within an opponent territory becomes forfeit
if that opponent's King is mated or stalemated before the pawn can attain
promotion.