You can do this on the SUNDAY Airlines website.
To do this, go to Additional Services - Additional luggage and select one or two bags of additional luggage up to 23 kg per passenger. Pay for the order by bank card, confirmation of purchase will be sent to your email.
This service is available only if you have an issued air ticket

Where to search?
Simply click on “Additional Services” - “Select a seat on board” section

How do I proceed?
Enter the surname in Latin (example - FAMILIYA)
Passport number with a series (example N12345678)
Flight number, numeric only, example (5237)
Flight departure date (01.01.2025)

How to issue?
Once you have made a booking for a passenger, click on the “Buy Services” button
Select a service
Enter E-mail
Click on the “pay now” button

Piece concept stands for luggage space, the number in front of PC stands for the number of suitcases. Remember that the dimensions of your luggage must not exceed 158 cm in the sum of three measurements: length, width, height. The weight of allowed baggage is 23 kg on the airline's charter flights.

If you have more items than the fare allows, there is a way out: buy an additional piece of luggage.

1 place 23 kg width+height+depth 158 cm
International flights: 30 USD

1 place 23 kg width+height+depth 215 cm
International flights: 35 USD

1 place 32 kg width+height+depth 158 cm
International flights: 40 USD

1 place 32 kg width+height+depth 215 cm
 International flights: 45 USD