Overstay Visa Penalties must be paid online via the sponsor
company Metrash 2 account or through the MOI E- Services, in your case the penalty must be paid at the Airport Immigration by your PRO by ATM card on the same day of your flight.

The above response is provided by GTG Qatar. Contact them for all your visa-related needs: +974 4442 2033 or visit www.gtg.qa