Here are some steps you can take to troubleshoot the issue:
1. Check the window switch. Make sure that the window switch is working properly by testing it with another window. If the other window works, then the switch is likely not the issue.
2. Inspect the window regulator. You can usually access the window regulator by removing the door panel. Once you have access to the regulator, inspect it for any signs of damage or wear. Look for broken gears, frayed cables, or any other damage that could be preventing the window from moving properly.
3. Test the window motor. You can test the window motor by applying power directly to it. If the motor works, then the issue is likely with the regulator or the switch.
4. Replace the window regulator or motor. If you find that the window regulator or motor is damaged, you will need to replace it. This is a job that is best left to a qualified mechanic, as it can be tricky to do yourself.