I have a custom connector (OAuth 2.0 with Generic OAuth 2 identity provider) that I built and when I test it, it works and gives a 200 response.
But when I try to use it, the authentication will expire an hour later.
Here is the API reference for authentication:
https://developers.ringcentral.com/api-reference/authentication
I'm guessing I don't have the correct refresh URL?

I switched to the swagger editor because I've never done that and wanted to see if there was something in there I could use to find out why the authentication is expiring.
There's an authorize button in the swagger editor, so I press it. Then fill in client ID and secret and press another authorize button.
It opens another browser tab to this URL:
And I see this in my browser:
{
"error" : "invalid_grant",
"errors" : [ {
"errorCode" : "OAU-109",
"message" : "Redirect URIs do not match"
} ],
"error_description" : "Redirect URIs do not match"
}
Just wondering if my issue is really because there is some problem under the hood due to mismatched redirect URI?
Also wondering why when I enter a Refresh URL in the UI and save the connector, it doesn't show up but the Authorization URL and Token URL do (see above picture)?
Any help would be appreciated.
Thanks
John