SSO to OKTA from external application

I want to implement a Single sign on by connecting two apps. the requirements is that when a users logs into the my application, it uses its native authentication method, but fires API authentication to OKTA to automatically log in the user into the New App which I added to the OKTA application portal.

I am using the OKTA application link as a embed link in my local application iframe, so whenever the iframe is loading is always pulling the OKTA login widget for authentication, i want to bypass this authentication by using any auth api. I can see OKTA have api/v1/authn where i have to pass username and password of my OKTA user account and it returns a sessionToken with success message.

But i don’t know how to use this API response to get my requirement done. Appreciate your help!

You can use the /authorize call with the session token.

What type of application in Okta are you trying to login to, OIDC web app, SPA?

Correct me if I am wrong, I am totally new to this SSO concepts. I just want to view a report which is hosted on the Tableau online from my web application build using angular and .net . So I used Okta for the Additional SAML authentication to behave as the Identity Provider. So now I just want to automatically login to Okta from my application to view the embed report using any API call or passing any accesstoken. Is that possible?

Does the user’s password exist in Okta or in another Identity Provider? How do users log into Tableau, is it through Okta?