There is no feature on the LG smartphone to turn off Wi-Fi Direct in general; to turn off Wi-Fi Direct, simply disconnect all connections.

Android 9 | LG UX 9.0
Step 1:  Open the  Settings
Step 2:  Tap on  Wi-Fi
Step 3:  Open the  Menu
Step 4:  Tap on  Advanced Wi-Fi
Step 5:  Tap on  Wi-Fi Direct
Step 6:  Tap on  Connection
Step 7:  Confirm with  OK
  1. Open the Settings
  2. Tap on Wi-Fi
  3. Open the Menu
  4. Tap on Advanced Wi-Fi
  5. Tap on Wi-Fi Direct
  6. Tap on Connection
  7. Confirm with OK

LG Instructions