Yes, you may do so by contacting a Qatar Airways office. You can also upgrade on qatarairways.com or our mobile app.
Please note that you will not be able to benefit from the fare of the upgrade offer, when upgrading your class of travel on any other flights in your booking. The upgrade offer is only applicable to the flight(s), of which the flight number(s) is/are indicated in the email announcing the offer.
If you would like to upgrade your class of travel on any other flight in your booking, the full upgrade fare will apply.