You can move the task in one of the To-Do lists, between To-Do lists, or from a project to a project.
How to move tasks within one project
Each task can be moved via drag & drop (click by mouse and pull the task where you need).
How to move tasks between projects
Moving task between projects can be done through the context menu (three dots) in the right part of the task. Select the Move… option:
The form appears below the task name. Choose project and To-Do list and click on green button Move task.
You can also move a task in the To-Do list column view of kanban board: