The "No command" screen is a security feature. To actually access the menu options, you must bypass this screen:
If your NOKIA C20 is acting slow but you don't want to lose data: How to Open Recovery Mode on NOKIA C20
Always back up your important files before performing any "wipe" or "reset" operation. For most performance issues, simply clearing the cache partition is the safest and most effective first step. The "No command" screen is a security feature
Phone will reboot directly into Recovery Mode (bypassing “No command” screen). let go of all buttons
If the phone keeps restarting, let go of all buttons, let it boot up normally, turn it off, and try the process again. or clear the cache partition now that you know how to access this menu?