Proxmox is set to bridge and works with ipv4 without any problem.
But the problem is probably elsewhere, I tried opening the ipv6 test page on my laptop and it said my provider doesn't support ipv6, which is bullshit. I actually have two public ipv6s assigned from it.
So I would need to somehow run the installation with only ipv4, is it possible to do that?
@madmaneighteen can you share a bit more about your environment? Also when the routing and possible portforwarding are correctly setup, you should hit nginx on your Cloudron there, so for a start check if nginx is running in your Cloudron server systemctl status nginx and also maybe try to curl localhost within the server to ensure nginx is also responding correctly there at least.
Just my 2 cents here : like girish said, if you want to run other things besides cloudron, you should install cloudron in a VM.
If you really want to dedicate the whole machine to cloudron, there is really no need to bother with the additional layer of complexity, another OS to keep up to date and such. I would go bare-metal in this case. That's how I've been running cloudron for 2 years, and it's great.