To free up internal storage on your phone:
Open the Files app and tap 
Or, go to Settings > Storage, then tap 
If there are media files to move, tap the option to free up space.

You cannot store apps on the SD card because it is portable storage. If needed, you can free up space on your phone.
Drag the SD card notification down, and tap Eject.
If you don't see the notification:


It's now safe to remove the card from the phone.
To insert the card into another device (computer, projector, etc.) that uses different card dimensions, you may need the adapter that came with your card. See device manufacturer's instructions for the type of adapter required and insertion instructions.


If you’re having issues, try these troubleshooting steps.