Buildbox - SoundBible is a great #indiedev resource to use to find free sound effects for your games. They have tons of themed sound clips from heavy rain to a hyena laughing!
Top 5 Free Sound Effects Resources to Kickstart Your Collection - NewBlue
Free sound effects • Uppbeat
12 Great Places To Get FREE Soundbites - Updated 2021
Over 280 Free Sound Effects for Videos, Apps, Films, and Games