edit extras

How to  edit  or deactivate an extra :

Click 'Manage extras' button in the menu. So you can  see your activated extras. You can edit or deactivate them. 
For editing, click 'Edit extra'¹ button.

For deactivating the extra click 'x'² button

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General view of Your extras page:

 

How to add a new extra :

Click 'Manage extras' button in the menu. So you can add a new extra by clicking 'Add extra'³ button! After selecting the extra⁴, click on 'Add extra'⁵ button! OK!

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General view of Add extra page:

 

After adding an extra, do NOT forget editing the extra's options!!