An extra garage door opener is good to have.
The remotes are programmed uniquely to open your door (and not your neighbor’s). You may have lost one remote or need an additional one for whatever reason. If you cannot obtain a remote from the original source, universal remotes are available at many hardware and department stores. You will need access to your control panel to program the remote.
Purchase a universal garage door opener.
Follow the steps provided in the manual included with the remote to program the device to work with your garage door system. This will generally involve setting switches and pressing buttons on the clicker to sync it with the system.
Test the remote by clicking the appropriate button, indicated by the included instructions.