Delivering Checkmate With Knight and Rook

So the other day I was just practicing with the engine 2 connected pawns (1 being a rook pawn) and rook, against only rook. Just for fun I decided to underpromote to a knight. In the end I had a rook and knight against a lone king and was wondering if it was possible to DELIVER checkmate with the knight. At first I thought it would be simple - If a bishop and knight can both deliver a checkmate together, surely a rook and knight could as well. After trying and trying I can’t seem to force a position where the knight can deliver the checkmate even with the help of the rook. I know it’s easy to checkmate with the rook but I was just curious if it is possible to force mate using a knight with the help of a rook against a lone king.

It is is possible, eg Black king on a8, White king on c6, Rook on b7, Knight on c4, Nb6#. But, for this position to occur BK had to be on a7, then Rb7+, then for this to happen, black had to play Ka8, but to avoid mate in 1, they could play Kc8 and no mate with knight. So technically it is possible but against best play, I guess there is no mate with the knight.

Sorry, BK had to be on b8