Please share the flow to get ID token, Access Token and Refresh token for server side application

Currently we are using Okta openId connect authorize API. This endpoint is not a JSON API. We are looking for Json API to return authorization code or if we can skip authorization code flow and get tokens (Id token, access token and refresh token). Please share flow and app configuration information.

Check out this guide Implement authorization by grant type | Okta Developer

We were trying to implement above mentioned Authorization code flow with PKCE but as I mentioned /authorize endpoint intended to be front channel endpoint that redirect the browser to. I am looking solution for server side app. Calling rest API to return response in json format

Server-side apps can and should redirect the user to the authorization endpoint just like any other application.

After the user is sent to the authorization endpoint, they will be redirected back to your server-side app, where the user’s browser will send your app the authorization code in the query string. Your app will then send that authorization code in a POST request to retrieve the access and refresh tokens from Okta.