What your garage door button looks like and where it’s located on your machine depends on what brand and type of opener you have. Typically, the “Learn” button on your garage door opener should be located towards the back of the machine, above the antenna wire that hangs from the motor head. It may also be under a light cover. And usually, you’ll find this brightly colored “Learn” button to be either green, red/orange, purple or yellow.
If you need more help locating this, have an experienced garage door technician look into the problem.