Your center screenshot is the testing base URI for an extension.
Not the redirect URI for the oAuth client.
So if your application is an extension then you are adding the redirect URI in the wrong place. Top right of the extensions UI is [extension settings]
In there you will find the OAuth Redirect URL field. That is where you should be setting the Redirect
If you have created an Extension Client ID in error, then you need to create a “regular” Application ClientID instead.
And that only has the one page
