one of my drones propellers is not working I need help

Sounds like a bad motor. Replace the motor.

Did you try to replace the motor? It seems to me that this is the only way to fix your drone. But I think that in this case there will be another problem. Sometimes it is very difficult to find the right parts for repairs, especially to find a new motor for a particular model of drone. Unfortunately, these devices are not yet very popular and numerous, so there are few details on the market. If you won't find the new motor, than I recommend you to search for a new drone. Take a look at this article https://buyersimpact.co.uk/ there are many reviews at affordable models of drone.