Garage door opens fine by itself but in order to close the garage door you have tm manually hold the button down. Any ideas of what's wrong thanks.

There is an electric "eye" near the bottom of the door. Actually one on each side. This is a laser. They have to be aligned and unobstructed for the door to close. This is a safety feature, started back years ago kids started getting hurt by doors closing on them. (Or so it's said.) Make sure there is nothing blocking the eyes, and that they are aligned properly.

Tommy is correct. The last door I worked on had an issue some days and some days not. Turned out to be a bunch of plastic shopping bags sitting in the corner by the door moving around in the breeze.

In addition, of the motor senses a drag, it will reverse. That is one of the tests they use. Make sure the track, chain and rollers are well greased and the track is straight.