Go to this post https://forums.knack.com/t/integration-with-stripe-customer-portal/11306/9 and scroll to the bottom and read my reply and watch the video and see if this gives you some ideas that may work. I never completed the entire project as I am now integrating and using an entire CRM and digital marketing and automation system that integrates with Stripe and Paypal for this purpose that we will be marketing for purposes beyond Knack. But if you are interested in either solution, the one in the post requires an integration I mention in the post. The other is a much broader wholistic solution to manage a business which includes websites, funnels, communication, workflow automations, social integration… I then integrate the active vs inactive subscription back into Knack with Pabbly.