Go to the Create Campaign page for the Report Campaign.
First, create the Cover Page you want to save as a Template.
Click on the EDIT COVER PAGE button near the top left corner.
A window will open.
Make any changes you want.
Click the SAVE button in the bottom right corner of the window.
The changes you made will now appear in the Report Preview section on the Create Campaign page.
To now save this as a Template.
Click on the Menu Icon near the top left corner.
A menu will open.
Click on the Save as Template item.
Now this Report will appear in the Template Menu.