Can I connect to my IPv6 DietPi Server from an IPv4 address?

I have a Nextcloud server on my DietPi that works fine, but I noticed that I cannot access it from certain places. What all of these have in common is that they seem to use IPv4.

This would make sense, as IPv4 is not compatible with IPv6, and in DuckDNS, I used IPv6. I tried to set up IPv4 with port forwarding, but it didn’t work, so my guess is that my ISP has IPv4 behind a NAT…

This is such a pain, because I cannot access the server from any IPv4 WiFi connection or even my own mobile data because they don’t support IPv6.

I heard that SSH Tunneling and Wireguard could help to make this work, but I don’t find a ton of resources on how to do that, and I tried setting up Wireguard with PiVPN, but it just doesn’t seem to work because it’s trying to use IPv4, that, as I’ve mentioned, seems to be behind NAT, making it not accessible remotely.

Is there an easier or better way to do this?

The only solution I can think of is to have a virtual server accessbile on both IPv4 and IPv6 and use it as an aggregator for the vpn tunnels. Then you can connect from the ipv4 only mobile internet to the virtual server and route to the tunnel going to your home.

Maybe something like Tailscale could allow remote access.