With the volume buttons on the LG smartphone, we can choose to stop the alarm, snooze or mute it, or if none of these options are desired, the alarm buttons can be disabled completely.

Android 9 | LG UX 9.0
Step 1:  Open the  Clock -App
Step 2:  Open the  Menu
Step 3:  Open the  Settings
Step 4:  Tap on  Volume key behavior
Step 5:  Choose between  None ,  Snooze, Dismiss  and  Silence
  1. Open the Clock-App
  2. Open the Menu
  3. Open the Settings
  4. Tap on Volume key behavior
  5. Choose between None, Snooze, Dismiss and Silence

LG Instructions