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We both had one knight and King

Rock the knight back and forth or your king. Sooner or later the 50 move rule will apply. Just keep your knight away from your king! No opponent can force a checkmate if this is done this way !!

lichess.org/editor/k7/2N5/1K6/8/8/8/8/7n_b_-_-_0_1?color=white

If your knight helps your opponent, than it's like there are two knights against you and your king also must help your opponent to be mated. It's only possible with a help mate scenario or when you are very low on time and premoves don't help.

Running around the outer center will do fine too.
lichess.org/analysis/8/8/3k4/4N3/3K4/8/8/7n_b_-_-_0_1?color=white