I was quite sure in 2015 the power folding option was available. I'd check again, if not
these will work, but they aren't cheap, and they aren't from the dealer either.
You can swap tow mirrors from another Ram, but not below 2013. In 2013 they started putting the temperature sensor in the mirrors, which controls some aspects of the computers engine controls, therefore if you put an older than 2013 mirrors without the sensor, you will get a check engine light.
You will need to take it to the dealer to flash the computer if you are upgrading to something you dont' have already, i.e. puddle/signal light, auto dim, power folding etc And if you are deleting something you do already have, like power folding, it is possible it could introduce an error code.