When you insert an optional SD card for the first time, it is recommended that you format it.
Caution: Formatting an SD card permanently deletes all data on it.
- From home, tap Apps > Settings .
- Tap Device maintenance > Storage.
- Tap More options > Storage settings.
- Tap SD card > Format > Format.
- All data on the SD card is erased, and the card is formatted for use on your phone.