For Enabling to developer Mode In Redmi Note 7 :
1: Go to Setting.
2: Click to „About phone” option.
3: Press 7 times to „MIUI version” option.
now you will see a Toast message „now you are developer”.
=> Now you should install to Mi PC Suite from this .
1: Install the pc suite with connected your redmi.
2: Now go on Permission in setting and click „install via USB”.
=>For Enabling USB Debugging :
1: Open Settings > Additional settings > Developer options.
2: Firstly enable to developer options then go below and find USB Debugging and enable it.
3: When your pc suite open then again repeat disable and enable to USB Debugging