Scenario
You have tried to set up Stripe under Event Setup > Payment Methods. Still, you are seeing an error message that says something like "If asked, please quote to support: {'provider': 'stripe,' 'code': 'unknown,' 'exception': PermissionDenied()}."
Quick start
Find your original HeySummit subdomain. This can be seen under Event Setup > Settings > Event Domain > Standard Domain. It will look something like "your-event-name.heysummit.com."
Open an incognito browser window. Using an incognito browser helps ensure that no cookies are being used in that session. Some providers rely on cookies and require refreshing every once in a while. So, providing a fresh session ensures everything will be up to date and the site should work fully as intended.
Navigate to your event using the original HeySummit subdomain (the URL that looks like "your-event-name.heysummit.com," not your custom domain or just heysummit.com) and log in with your Event Organiser account (the subscription holder, rather than Team Member account).
Try connecting your Stripe account to HeySummit again.
Please note: You can only connect the Stripe account to your event while logged in as the Event Organiser.