@sorinmax You question is not really connected to the topic of the thread. So it is better to open a new thread: “How to install umbrelOS on proxmox?” There you also can tell what hardware you have and how much you know about umbrelOS and proxmox…
Update: There is already a thread about proxmox:
https://community.umbrel.com/t/umbrel-1-1-on-proxmox/
Just use search function in forum… 