Click the Manage button and select the Courses option. Click the settings menu and select the Assign Master Section option.
The Assign Master Section modal box will open. Select the instructor from the Instructor List drop-down to whom master section is to be assigned, select the section from the Section List drop-down if required. Finally, click the Save button.
To clone a master section, click the Manage button of your desired course. Now, click the three-dot menu on the course and select Copy configuration from option.
The Copy configuration from modal box will open. Select the Clone Using Master Section option from the drop-down. Finally, click the Save and Manage Section button.