@salmanfaris I've not used the same version of the stepper motor that you've mentioned but I've used 12V stepper motor with ULN2003 motor driver. So probably I can help you with the queries.
Firstly all the tutorials on the internet show how to connect your motor's wires to ULN2003. But, in reality when you buy those motors the wires color codes may be changed, so in that case, we need to use a multimeter and check the resistance of the wires. 2 wires will have the same resistance and other 2 wires have the same resistance and the leftover one is a ground wire. This way we can get to know which wire must be connected to which port of ULN2003 driver. This is the common doubt all get while using ULN2003.