send da puzzle
What do I do when I can't solve a puzzle??

Do Puzzle Rush
Ur a diamond member
After u do some, then focus on the book again
Btw does the book teach Tactical Chess or Positional Chess??

Do a CCT scan = look at all Checks Captures Threats. If none work search for loose pieces and/or a weakened king position. None of that search for weak squares.
If all that fails you're either missing it or it's some positional aspect you can use to your advantage. Can't help you there. I'd look at the solution after max 20 minutes or so. No point mulling over it for days.

If the puzzle in a book is simply too hard or you're just not "getting it," just look up the answer. It might be something you don't know about, or it might be a mental block for this one position. Once you know the answer, try to ingest it and all the variations, and explain to yourself why you didn't get the answer. Then come back to it a while later and try to do it again.

I am 2930 in puzzles (3038 is my peak):Here are my tips:
First understand that all puzzles have solutions so your main thought should be any possible ways to checkmate your opponent or have a material advantage. Go through this checklist:
If the king has limited space: LOOK FOR CHECKS AND EVEN CHECKMATE
if the king has lots of space: it is most likely to gain material or to survive if you are really down in material
Also, i find it hard to study puzzles in books . Instead i find youtube videos such as
https://www.youtube.com/watch?v=PyDB2xiwx6U
This is Gothamchess, he is the reason that i am this good now lol.
I hope this is helpful. Good luck!
I have many puzzle books but when I get stuck on one I have no idea what to do, I usually leave it to try again another day but then come back and continue to stare blankly at it. What thought process can I incorporate when I just have no idea what to do in a puzzle?