Google the make and model and reset your remote using the buttons on the drive motor.

Check your alignment sensors. They are the two little boxes on each side of the door near the bottom of the door. make sure they are straight across and pointing directly at each other. If they are not, that could be your problem. Also make sure nothing is in the way of the sensors reading each other. there has to be a direct path from one to the other.

Did you say the unit works from the keypad, but doesn't respond to the remote(s)?

If that is the case, the unit most likely needs reprogrammed to recognize the remotes.

Note: The process requires ALL remotes you want to work to be present at the same time. Adding a remote DELETES all previously programmed remotes.

Is there any chance you attempted to add a remote and didn't reprogram the remote you are trying to use at the same time?

Your gears in the opener are stripped out. The gears from the motor to the chain sprocket are made of nylon, and over time they wear out. They take a beating when a door is stuck, etc. You can buy replacement kits and install it if you are a DIY, or have a garage door installer install it and reset your door and fix things up.

Battery? Or it needs to be reset.