You must apply for the transit visa at least 7 days (excluding public holidays in Qatar) and a maximum of 30 days prior to your intended date of arrival to Doha, Qatar. Entry to the State of Qatar with approved visa must be within 30 days from the date of visa issuance. Passengers are requested to keep this in mind while plafollowing nning their itinerary and visa submission.
Please contact your local Qatar Airways office for further inquiries. Contact details can be found in the link https://www.qatarairways.com/en/worldwide-offices.html