How to find stepper motor's rated current to set current limit?
No, you have the right rating, it is just that you have a much better motor than in the tutorial.

The motor in the tutorial is a high voltage, low current one.  The problem with this is that as a result it has a high inductance, and meaning that it take a while for current to rise to the rated value after each step, which means that the torque when stepping rapidly will be much less than the rated torque.  To overcome that, a higher voltage driver (say 36 volts) would be needed with a chopping current regulator.

Your motor with a nameplate spec of 1.68 Amp per phase will be built for a lower steady-state voltage (probably around 3-4 volts, though that is only a guess), and will have a lower inductance.  As a result, it will probably perform well when used with a chopping current regulator powered from 12v.

Of course it is possible your current driver is not rated to provide that much current.

Decent 3d printer kits for example may supply low voltage high current motors for the X and Y axis and extruder; but they often cheap out and supply a high voltage low current motor for a screw-drive Z axis, figuring that the Z axis does not need to produce a lot of torque (or if direct drive, does not really need to move very quickly).   A yet better kit might use decent motors there, too.