Hi (Clients Name) —your  payment on (Enter Date) was declined. Please update your payment info here to keep your website services: (add link here)

to get link to subscription payments:  Log into Stripe -> Customers -> Subscriptions -> Select the 3 dots (...) for the drop down menu -> Select "Share Payment update link" -> select the clipboard icon next to "Share Link" and paste it in message above where it says "add link here"