Performance Test Speed

Hello Dear Team

I'm Trying to run a performance test but i get an error message everytime i run the test :

"The performance test didn't return any results. This probably means you're on a local website (which we can't scan) or something went wrong trying to access WPMU DEV. Try again and if this error continues to appear please open a ticket with our support heroes "

Can i get some help or explanation please ?

Cordialy