This redirect loop issue has been reported in multiple places.

The issue (from what I've read) appears to be with the introduction of the new UI for the OAuth Consent Screen.

Some people reported to have gained access to this page by using one (or more) of the following:

1. Different browser (or private/incognito)
2. Deleting and re-creating the project
3. Use a login link that redirects to the oauth consent screen
4. If the app is for external audience, set yourself as a test user

If none of the above worked for you (it didn't for me), I recommend subscribing to the posts below in case any updates arise:

1. Clicking OAuth consent screen in Google Cloud console redirects to Overview page
2. https://www.googlecloudcommunity.com/gc/Community-Hub/Problem-with-Oauth-consent-screen/m-p/913303
3. https://www.googlecloudcommunity.com/gc/Google-Cloud-s-Observability/Cannot-access-OAuth-Consent-Screen-setup-keeps-redirecting-to/td-p/908771
4. https://www.reddit.com/r/googlecloud/comments/1l3zi9q/help_google_cloud_console_redirects_me_from_oauth/
5. https://www.reddit.com/r/devops/comments/1isamvc/cant_configure_a_consent_screen_clicking_on_oauth/
6. https://community.home-assistant.io/t/google-drive-oauth-consent-screen/842720