Tesla Fleet Integration - Need help please!

Hey all. Its 3am and I’m at my wit’s end.
I want to use the tesla fleet integration and I cannot get it to work. As a bit of background, my ISP uses CGNAT, so I cant port forward.

So far, Ive generated public and private keys. Both are in my HA config folder. The public key matches one I’m hosting on github using cloudflare for a tesla to see it. When I run the curl commands in HA, it is showing the key, and they do match.
In my tesla developer account, the allowed origin is the domain I purcased, and the direct url is the usual Link to OAuth2 Authorize Callback – My Home Assistant.

When I try to add the integration and put in my details, it just get a ‘Something went wrong, try again later’ message.
Can anyone help? I’m desperate to get it to work.
Thanks in advance all.
Daithi.