Using REST API to initiate OAUTH

Using the available documentation for creating an OAuth2 Token, the successful response I get is not documented and I do not understand how the authentication flow should proceed.

After the initial GET request to https://cloud.appwrite.io/v1/account/tokens/oauth2/oidc, I receive a HTTP 200 response containing: -URL: https://oauth.provider/ui/login/login?authRequestID=280000000043

• Cookies: CSRF and Useragent
• html of the login page from the oauth provider

How do I proceed with the authentication flow using the data AppWrite has sent in response?

After manually changing the Useragent cookie value, authentication proceeds, until it hits appwrite and the following error is shown:

Missing redirect URL Your OAuth login flow is missing a proper redirect URL. Please check the OAuth docs and send request for new session with a valid callback URL.

https://cloud.appwrite.io/console/auth/oauth2/failure?error={"message":"Failed to obtain access token. The OpenID Connect OAuth2 provider returned an error: invalid_request: code_challenge required","type":"user_oauth2_bad_request","code":400}