Assuming you have a model that has the 4WD drivetrain option, engaging 4 wheel drive on a 2017 Dodge Ram 1500 is simple. There are two ways to do it:
The first way is to turn the knob on the center console to the 4WD position. This will lock the front and rear driveshafts together, providing power to all four wheels.
The second way is to press the button on the center console labeled 4WD. This will engage an electronic transfer case, which sends power to all four wheels.