[help] yunohost ipv6 only

Hi librehosters,
I wanted to set up my yunohost and host some things. Before buying the Respberry Pi 4, I want to use for this, I set it up on a VPS. I managed to host everything I want (on the VPS).
So I bought the Pi4 and installed it, booted it, registered my domain,… .
My problem is that I can’t open ports for ipv4, but I can only use Ipv6 exposure with my ISP Vodafone (Germany).
So I ask you guys if you could help me with setting up yunohost with ipv6 only and at best walk me through it one by one.