Disable vertical drag and drop for few tasks

hi, i have sceneario where vertical drag and drop is enabled for few tasks and disabled for few tasks, how to disable vertical drop for few tasks?? please help

You can use onBeforeTaskUpdate event handler and return false for the tasks with the certain condition. If a task fits that condition, you won’t be able to vertically reorder that task.
In the following example I disabled vertical reorder for the tasks with the “duration” more than 2 days:

You can learn more about that event handler in the following article: