I tend to use whitenoise when me and my fiance sleep apart. Like when I am at a conference. Im used to his snoring when I sleep and the silence is deafening without something.
I often use this FLOSS android app: https://f-droid.org/packages/protect.babysleepsounds
Audio files it uses are in the github repo: baby-sleep-sounds/app/src/main/res/raw at master · brarcher/baby-sleep-sounds · GitHub
Before that I would just search for sounds of rain on freesound.org sorted by durration. https://freesound.org/search/?q=rain&f=&s=duration+desc&advanced=0&g=1