01) Access the Control Panel

02) After login click on Catalog

03) Create a Category Subscriptions

04) After creating a new product

You will have the Recurring Payment field

Select YES

Fill in the period and frequency

05) After clicking the button to Add / Update the product

06) You need to configure the PayPal Payment Module in the Control Panel >> Modules >> Payment >> PayPal

Note: Automatically will be charged monthly subscription through PayPal