This has been an awful campaign. 3 nights in a row I've wasted me time trying to register. Maybe my country's pool is so small that it's really useless and hopeless, but I've been trying multiple browsers on multiple computers at slightly different intervals, I always get "error while submitting the form" and the next time it happens to work, I get the notification that "The daily promo code limit for your country has already been reached. The allocation is refreshed daily at midnight Doha time (GMT+3) - please try to register again tomorrow."
The rules state that you really cannot change your country, as they will check that during check-in. "It is mandatory to present the original medical identification at the airport check-in desk at the time of departure, and it must clearly state the occupation and country of employment as submitted on the offer registration form. No photograph or printed identification will be accepted."
This has been a complete waste of time and has deprived me of my sleeping time... I'm so pissed I will avoid Qatar when flying resumes. It would have been more fair to just accept the forms and then make a daily lottery who gets the free flights and who doesn't. This marketing ploy failed big time.