I second @kitedemon 's caution about the warranty. We’re all glad to help, so we’ll offer some suggestions, but when it comes to anything that involves changing parts (other than nozzles), check with tech support first.
That having been said, you can best get help from us by asking a more detailed question. Just saying “which isnot working” covers a lot of ground. That could mean everything from the print head isn’t moving at all, it’s moving on one, two but not all three axes, the print head is crashing into the build plate, It’s making a grinding noise, the print head or bed are moving in a direction opposite from what you would expect, the gantry only moves up but never down, etc. etc.
Those are just some of the movement-related problems I’ve seen in the last 6 months.
Specifics are always more helpful. Or if you aren’t sure what it should be doing, describe what it does vs. what you were expecting. Photos and / or video is also immensely helpful in some cases where something is difficult to describe.
Before you go messing with the firmware, give us more details. They generally work when straight from the factory although I can think of one item specific to the Ender 5 Pro where they changed a hardware component but didn’t change the firmware to accordingly. I haven’t heard of this with the Ender 3 Pro, however, that doesn’t mean they didn’t do it there too.
So, more details, please, and we’ll guide you accordingly.