How to connect Google Assistant using the Cloudflare tunnel

I have followed all the steps in the integration guide and the post above, but I am always getting a “Cannot reach [test] myapp” error when trying to link google home.
I have the WAF rules from here https://community.home-assistant.io/t/how-to-connect-google-assistant-using-the-cloudflare-tunnel/545574/23 and I am able to access my external url from the HA app and outside network.
I tried disabling the WAF rules altogether, but it still doesn’t work. I do have access rules setup for some emails and the one here https://community.home-assistant.io/t/howto-secure-cloudflare-tunnels-remote-access/570837.

My configuration.yaml lines are as follows:

google_assistant:
  project_id: my_project_id
  service_account: !include SERVICE_ACCOUNT.JSON
  report_state: true
  expose_by_default: true

I get 405: method not allowed when I try to access my /api/google_assistant and /auth/token from both my external and internal url.

Do I just need to wait for some time or is there something I am missing?