QR codes can also be scanned with the camera of the Samsung device. if there was a separate mode in the past, newer Samsung devices (from Android 10) can detect and scan QR codes via the normal photo mode of the camera app. In order for the camera to detect the codes, the function for this must be activated in the settings.

Android 10 (One UI 2.0)
Step 1:  Open the  Camera -App
Step 2:  Open the  Settings
Step 3:  Enable or disable  Scan QR codes
  1. Open the Camera-App
  2. Open the Settings
  3. Enable or disable Scan QR codes

Samsung Instructions