Wife and I have a stopover in Doha next month. Then a second stopover on the way back in Doha two weeks later.

Need to get a transit visa for Qatar.

1) When do I apply for the transit visa?
2) Will I need a visa going there, then another visa for the return trip?
3) Website says to enter the PNR and last name. Because I booked RT for both of us under the same PNR, will it cover both of our visas and for both ways?

Thank you