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To do so, you should configure every item that can be paid by subscription, individually. Go to the menu on the left side of your screen > "Products" and search for the product you would like to configure by writing its name or scrolling the list.
To pay for a subscription product, it is mandatory to have a customer account. For guest mode customers who have a subscription product in their cart, the creation of a customer account is requested before making the payment.
On the product sheet (when you click on the name of the product), you can go to the "pay by subscription" tab on the bottom right side of the screen.
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