The pending payments from the customers will be reflected in the Missed/Upcoming Payments in the dashboard.
You can see the payment pending in the Subscription list as well as shown below:
You can find the Missed/Upcoming Payments in the Dashboard as shown below:
If you click on the Missed/Upcoming Payments then it redirects you to a new page as shown below:
To bring in notice to the customers his pending payments and to initiate the payment again, click on the BOOK.
This is the redirected page after clicking on the BOOK button as shown below:
Then after clicking on the Yes,Book then the transaction gets charged and when the payment gets successful then the payment shows successful in the subscription list as shown below:
If the payment was successful this will be reflected in the Missed/Upcoming Payments.
Then for the verification that the payment was successful, look in for the Payouts module from the menu to find the successful transaction reflected as shown below:
Video tutorial for Subscription billing: