This is a SCAM. All job related recruitment and hiring related with Qatar Airways should be coming from Qatar Airways Human Resources at Doha. There are so many SCAM coming from internet such as above and to make sure, verify the phone number of the company that you want to apply for and contact them directly.

One of my friend also got same invitation but with another airline company flying UK and we later on found-out that the job offer is a bogus one. My friend was asked to send payment for visa processing but fortunately, he checked with the airline company's headquarters and confirmed that it was a racket before be could ditch-out money from his pocket.

Just to be sure, contact Qatar Airways HR here at Doha.