This Is A very hard checkmate to get but I'll show you how first make sure you have 2 rooks/queens then make sure aswell you've captured all the opponent's peices and then get your king to the a2 h2 a7 or h7 then do the ladders mate towards your king once the opponent's king is looking at your king and the rook is behind it meanwhile another is below/above/left/right to the king make sure to gove the opponent's king a few squares to play or else it will be stalemate after that move your king where it isn't blocking the rooks check and since you moved the king to get the checkmate you officially got the checkmate with a king