Lichess classify puzzles by themes [0], you can practice on the ones you want. It has more than 500k fork-themed puzzles (of various difficulty) [1]. [0] https

Lichess classify puzzles by themes [0], you can practice on the ones you want. It has more than 500k fork-themed puzzles (of various difficulty) [1]. [0] https://lichess.org/training/themes https://lichess.org/training/themes [1] https://lichess.org/training/fork https://lichess.org/training/fork