MikeD-customer-portal | Stripe Developers | Page 1

I'm not familiar with a way to get to the customer portal from the Dashboard, but after some quick setup it's only one API call to create a new portal session.
https://stripe.com/docs/billing/subscriptions/integrating-customer-portal
https://stripe.com/docs/api/customer_portal/sessions/create

I'd recommend opening the portal in an incognito window as well just to make sure it won't clash with your dashboard session.

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