In most cases all you have to do is adjust the opener belt of the belt drive tightening it to ensure smooth running.
Tighten garage door belt.
The manual does not indicate how to solve this problem.
The belt needs to be connected with the tensioner loosened so that the tensioner can be used to take up any excess slack.
The specific procedure should be in the manual for your unit.
1 close the garage door.
This is a very simple job to do yourself in fact all you need to do is follow this simple 6 step guide.
Tighten the adjuster three full turns clockwise to add tension if the door closed and did not remain open halfway.
Step 1 closing the garage door before beginning use the garage door opener to close the door and fasten it.
All you need to get started is a step ladder a 7 16 inch wrench and a flat head screwdriver.
But basically assuming the belt is attached with enough slack removed the tensioner bolt should be able to taske up the rest of the slack once tightened.