Well as someone said it could be several things that caused the problem.
I have had the problem twice. KIWI steps.
1. 4 prong flat connector checked good with meter and steps worked OK for several operations after testing. Failed again, cleaned all connections in the cable found it had 12V but would not let enough current through to operate the steps. Plug was contaminated and corroded just enough to act as a resistor cleaning fixed it.
2. Steps refused to extend found a thread on this site with a video on replacing the motor turned out to be a Ford window lift motor I think 96 Thunderbird. Took old motor to Auto Zone and matched it up to a Dorman motor but don't remember the part number you have to get the correct motor by comparing the left and right side motor. Only one will work. Replacing fixed the steps $45.
They are not hard to repair (depending on your age) main thing is be careful if the steps do start to move they are very powerful so don't be in the way.