My vendors are reporting getting this message (copied below) when trying to connect to Stripe instead of their usual page (attached). This is more of an admin page for when I first set it up. Any idea why this would be happening?

Congrats, you’re almost done setting up your application!
After connecting with Stripe, your users will be redirected to a page of your choosing (this is just the default). Make sure to change the live redirect URI under your application settings to something that makes sense on your own server.
To finish the process of getting an access_token for your user’s account, you’ll need to make one extra API request with the authorization code we passed back. In this case, the code is ac_AXfeG7FSpQsaYxNIw1nCdQEjhp6qkT0P, taken directly from the GET parameters on the redirect.
For example, try this curl request (note that you’ll need to replace YOUR_SECRET_KEY with the application owner’s live secret key)

curl -X POST https://connect.stripe.com/oauth/token \
-d client_secret=YOUR_SECRET_KEY \
-d code=ac_AXfeG7FSpQsaYxNIw1nCdQEjhp6qkT0P \
-d grant_type=authorization_code

You’ll need to do this programmatically (we recommend some kind of third-party OAuth 2.0 library)—check out our OAuth tutorial for a more in-depth explanation! Or, head back to our getting started guide to get a sense of what what you’ll be able to do after your users connect with Stripe.