Retrieving users in the organization with Okta API

I built a Desktop application and I use Firebase to allow people to signup with Google or Microsoft and most importantly get an access_token that allows the client to retrieve the contacts in their organization (using Google Contacts API and Microsoft Graph API). Last week I was setting things up with a new user. She works remotely for a startup and uses Okta to access services.

When we tried to signup with Google, it just didn’t recognize the email, so that doesn’t look like it’s a viable solution. I was wondering:

  1. Does Okta offer an oauth2.0 workflow to authenticate the user?
  2. If yes, with the acess_token that is returned, is there an API to retrieve the users in the same organisation?

If not, how should I go around it to authenticate with Google?

Okta does support OAuth/OIDC, but the user would need to set-up an OIDC application within their Okta Org and provide you with the client details (endpoints, id/secret, etc).

However, Okta does not have a similar endpoint. While admins would be able to access this sort of information (to list/search all users in the Okta org), end-users would not be able to do so, so this will depend on the user in question.