E-Government Gateway

Why can BTK Internet Payments be made only through Garanti Bank and Isbank? (I don't know where to make Btk internet payments?)

"The fee must be paid to tax offices, banks determined by the Ministry of Treasury and Finance, or payment institutions which integrated into the system.
The fee must be paid by specifying the ID number and the IMEI number which belongs to the registered device.
You can access information about the subject you have mentioned, from “""Mobile Phone Fee Payment” service offered by the turkish revenue administration under the title of Institutions on the www.turkiye.gov.tr page.After payment, you can complete your registration by clicking “save imei”"