You don't. The existing providers only deal with spinning up VMs and containers.
Most of the operations and configurations that exist in Proxmox are not present in the providers, like SDN, firewall and the various storage options. The reason is that the API is all over the place and really badly documented.
Note that I still quite like the product. I have a 2- (soon to be 3-) node cluster at home and at this moment I have no plans to migrate away from it.
I looked into Incus but it's also far from mature, with an API and general data structure being full of inconsistencies, and again the documentation is not quite there.
