I usually go to the New York Times website itself for archive crossword answers, they have a really comprehensive database where you can find solutions to past puzzles. If that doesn't work for you, I've also had good luck with crossword tracker websites like Crossword Tracker or Archive Crosswords, they seem to have a pretty thorough collection of NYT crossword answers from recent weeks and even further back. Sometimes the answers might be a day or two behind, but overall they're pretty reliable and easy to use.