Please, can you add Serbian shipping provider City Express?
Tracking number from barcode on shipping label have 16 digits.
Group 1 <6 digits>
Group 2 <8digits>
Group 3 <2digits>
Group 1 define warehouse center.
Group 2 define shipment number.
Group 3 is for correction, it is not required for tracking.
Tracking URL structure
For a few days I will get API key and I can send it to you.
Thanks in advance.