How do you study endgame?

I've already studied some basic endgame like the lucena, philidor, two bishop checkmate, etc. But I think there is so much more but I dont know how and what to study. Currently, I am only solving endgame puzzles on lichess, but I am open to any advices.

To study endgames do puzzles and learn endgame principles

Jeremy silmans complete endgame course book shows you theoretical endgames by rating and is great reference material for which theoretical endings you should learn. Learning by book is dull for some people so you can use the book as your ‘checklist’ and then find lessons on chesscom/lichess or chessable, YouTube further explaining those topics.

If you want to get the most out of study time then get a coach and ask the coach to compile all the relevant material for you into a study plan. My students don’t waste time searching for this stuff because I find it all for them which maximises their study time but not everyone can afford that luxury.

For practical endgame advice check out Ben Finegolds endgame lectures on YouTube I find they are very helpful for anyone 1000-2100 chesscom as he’s lecturing a mixed ability class so there’s different levels of depth you can watch at and still take away new lessons. I have rewatched these a few times and they helped me get to 2080 rapid.