you need an endgame book. you can't "practice" endgames while you're playing. endgames need to be practiced before hand and then applied during a game.
A) Basic Chess Endings by Ruben Fine
B) 100 Endgames You Must know by Jesus De la Villa
c) Complete Endgame Course by Jeremy Silman.
I suck at end games and everyone just seems to become a GM when they have a few pawns and a king left. problem is in low elo's the games very rarely get to end games and I never have a chance to practice. Learning and puzzles are all very specific scenarios that don't show up. Where can I go to just play end games and learn them?