Horrid endgame, how to defend appropriately?

First ever post so bear with me! I recently had a frustrating lost. I’m preparing for a local OTB tournament and don’t have much time to play with work and all. I found myself improving quite a bit in the first two weeks just with tactics and playing longer games, but this game just made me realize how little I understand how to close out games. I usually play ok in the opening and mid game, but my end games are atrocious. I actually tried to play against stockfish on lichess after from move 25 before my blunder, and proceeded to lose 4 more times in this position at over +5 evaluation on level 6 for stockfish. When it comes to end game precision, I don’t even know what I’m supposed to be looking for when making a move, just completely lost as opposed to opening or middle game! Just seeing if anyone has any advice, I don’t know too many people who play chess and can advise at a much higher level.

Sorry if I’m posting a game incorrectly, not sure how to properly link it.

Check out this #chess game: fullforceRC vs dbstance1 - https://www.chess.com/live/game/100207338601

Well, in the game in question it's just a tactical blunder, not some principled strategic error. Remember this pattern and don't do it again.

As for the endgames in general, starting with the basics is what I'd suggest. Understand how K+p vs K works, then look at endgames that convert to those endgames, and so on. It's a long journey.