There are many articles online explaining how to change the default notification sound, but I found it hard to find one which explains how to do it for individual / specific apps.
There are many articles which simply (and unhelpfully) say that the app should have its own settings, so for those that don’t, here’s how:
Android
v9 “Pie”
There are quite a lot of steps here, and one in particular is not obvious.
It’s easiest to demonstrate with screenshots.
I suggest you open the relevant app just prior to following this guide.
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Open the main Android Settings Page by dragging down from above the top of the screen.
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Tap “Apps & notifications”
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Select the relevant app, probably from the recent apps list, but you might have to scroll through the list of all apps.
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Tap “Notifications”.
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Make sure “Show notifications” is turned on, and tap the relevant category (there may be only one), this is not just a checkbox.
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Make sure Show notifications is turned on here too…
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…and that the behavior includes sound.
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Tap “Sound”.
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Select your sound, and you’re done.
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