The Samsung device's side panel can be opened by default using the black bar (arrow) at the edge of the screen, but if you don't like the black or the size of the panel, you can adjust it in this respect and in transparency.

Android 10 (One UI 2.0)
Step 1:  Open the  Settings
Step 2:  Tap on  Display
Step 3:  Tap on  Edge screen
Step 4:  Tap on  Edge panels
Step 5:  Open the  menu
Step 6:  Tap on  Handle settings
Step 7:  Set  Style  (Color),  Transparency  and  Size  of handle
  1. Open the Settings
  2. Tap on Display
  3. Tap on Edge screen
  4. Tap on Edge panels
  5. Open the menu
  6. Tap on Handle settings
  7. Set Style (Color), Transparency and Size of handle

Samsung Instructions
Loading...

Transmitting...