Welcome to the community forum.
I uninstalled the stock keyboard (Gboard), so until somebody else can give more exact pointers …
Settings - System - Languages & input - Virtual keyboard - tap on your keyboard (probably Gboard) - have a look at the settings there.
The keyboard I use - Simple Keyboard - has a “Preferences - Sound on keypress” setting there.
(And I removed your other topic in the Help category with the same post to avoid duplicate topics.)