To remove all data from a memory card, it is sufficient to format it, and memory cards with the wrong file format must be formatted.

The formation can be done directly via the LG smartphone.

Android 9 | LG UX 9.0
Format -  Open the  Settings
Format -  Tap on  General
Format -  Tap on  Storage
Format -  Tap on  SD card
Format -  Open the  Menu
Format -  Tap on  Storage settings
Format -  Tap on  Format
Format -  Confirm with  Format
Format -  Tap on  Done
  1. Open the Settings
  2. Tap on General
  3. Tap on Storage
  4. Tap on SD card
  5. Open the Menu
  6. Tap on Storage settings
  7. Tap on Format
  8. Confirm with Format
  9. Tap on Done

LG Instructions