In most cases, when a memory card is inserted, the Samsung device will automatically detect it and, depending on the configuration, the memory card may still need to be installed or made available.

This guide shows how to install the memory card in the settings, in most cases a notification will prompt you to install it.

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Device care
Step 3:  Tap on  Storage
Step 4:  Tap on  Advanced
Step 5:  Tap on  SD card
Step 6:  Tap on  Mount
  1. Open the Settings
  2. Tap on Device care
  3. Tap on Storage
  4. Tap on Advanced
  5. Tap on SD card
  6. Tap on Mount

Samsung Instructions