Error: EPERM: operation not permitted, mkdir 'C:\Users\Anubhab' command not found: create-react-app
Open terminal
to go to "C:/Users>" type: cd..
then run: dir /x
// this will show you your short id: ANUBHA~1 for username: Anubhab Mukherjee
then run: npm config set cache "C:/Users/<short-id-you-got>/AppData/Roaming/npm-cache" --global
// in my case
// npm config set cache "C:/Users/ANUBHA~1/AppData/Roaming/npm-cache" --global
then run desired npx command
THIS MIGHT SOLVE YOUR PROBLEM