I found a way to set it using Terminal: osascript -l JavaScript <<EndOfScript ObjC.import("LaunchServices") $.LSSetDefaultHandlerForURLScheme(ObjC.wrap("tel"), ObjC.wrap("com.apple.mobilephone")) EndOfScript Replace "tel" with the type of URL to handle, and "com.apple.mobilephone" with the identifier of the app to handle those URLs. To find the identifier of an app, run: osascript -e 'id of app "Phone"' replacing "Phone" with desired app name. F.e. "Safari" or "Safari.app".

I found a way to set it using Terminal: osascript -l JavaScript <<EndOfScript ObjC.import("LaunchServices") $.LSSetDefaultHandlerForURLScheme(ObjC.wrap("tel"), ObjC.wrap("com.apple.mobilephone")) EndOfScript Replace "tel" with the type of URL to handle, and "com.apple.mobilephone" with the identifier of the app to handle those URLs. To find the identifier of an app, run: osascript -e 'id of app "Phone"' replacing "Phone" with desired app name. F.e. "Safari" or "Safari.app".