All users except collaborators on Business and Enterprise accounts can apply custom workflows to tasks, projects, and folders.
When you apply a workflow to a folder or project, new tasks created in that folder or project are automatically assigned the first status from the workflow’s active group.
Navigate to a folder or project and right-click the name.
Hover over Set default workflow in the drop-down.
Choose whether to set the workflow For tasks or For projects.
Select the custom workflow from the drop-down.
Navigate to the relevant project or folder.
Click the folder or clipboard icon to open the info panel (if it doesn't open by default).
Click Default workflows to the right of the info panel banner.
Select a custom workflow either for projects or tasks from the drop-down.