The Samsung device is automatically locked when the display is turned off. One UI from Samsung offers the possibility to set a timer that starts when the display is turned off. If the device is turned on again within the set timer, the device will be unlocked automatically. Unlocking by means of the display lock is therefore unnecessary. "Lock automatically" can be set from 5 seconds up to 30 minutes.

Note: "Lock automatically" is useless when Smart Lock is enabled.

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Lock screen
Step 3:  Tap on  Secure lock settings
Step 4:  Enter your Lock screen  Password / PIN / Pattern
Step 5:  Tap on Lock  automatically
Step 6:  Choose desired  Time
  1. Open the Settings
  2. Tap on Lock screen
  3. Tap on Secure lock settings
  4. Enter your Lock screen Password/PIN/Pattern
  5. Tap on Lock automatically
  6. Choose desired Time

Samsung Instructions