Outlook Addin Error Code 13005 for auth.getAccessTokenAsync - single-sign-on

Question

So I am trying to use single sign on in an outlook addin. I have registered my app at https://apps.dev.microsoft.com/.
In my Manifest I have
<WebApplicationInfo>
<Id>{myId}</Id>
<Resource>api://mydomain.com:3000/{myId}</Resource>
<Scopes>
<Scope>Mail.Read</Scope>
<Scope>profile</Scope>
</Scopes>
</WebApplicationInfo>
mydomain.com is actually a domain i map to my local IP.
Outlook accepts my manifest just fine. How ever when i call Office.context.auth.getAccessTokenAsync, I get the following response
{name: "Invalid application resource Url provided.", message: "Invalid resource Url specified in the manifest.", code: 13004}
How else should i write the resource url. Am i supposed to add this url somewhere else?
I followed https://learn.microsoft.com/en-us/office/dev/add-ins/develop/register-sso-add-in-aad-v2 and was able to get further. But now i Get {name: "Preauthorization missing.", message: "Missing grant for this add-in.", code: 13005}

Answer 1

I was able to solve Error 13005 by adding /taskpane.html to the end of my redirect URI in the authentication tab of my App Registration [Figure 1]. Originally I just had https://loacalhost:3000 as my redirect URI. Just make sure that whatever endpoint the user is being redirected to is the redirect URI. Seems simple but I spent a lot of time on this.
If you can't figure out what your redirect endpoint is, inspect the taskpane element and then look at the top of the tab. It should be something like DevTools - {localhost:3000/taskpane.html}?_... The text inside of the curly braces is the endpoint, make sure that the whole string is added to the Authentication tab in App registrations.
App Registration Page Example Picture
I hope this helps,
Lucius