The authorization endpoint is used to interact with the user and obtain an authorization grant (code). This endpoint should be visited from a browser as it displays a page with a login form where users can enter their credentials.
In order to use this endpoint your application must be registered within Karhoo auth service as a valid client (assigned with a client_id and with its redirect_uri whitelisted).
Upon successful authentication the user will be redirected back to the redirect_uri with an authorization code passed as a query parameter (e.g. https://your-app.example.com/oauth/callback?code=eBd...sd0). The code should be further used on /oauth/v2/token endpoint to obtain Karhoo access token which completes the 2-legged authorization process.