I'm looking to set up FreeIPA on Proxmox as a container instead of a VM, but I can't seem to find any templates for it in the available Proxmox templates. Is there a way to download the template offline and then add it to the Proxmox templates?
Correct. To use docker or podman you would install it inside a vm and then use the dockerfile to setup the Apps container like described in the documentation:
If you want to run application containers, for example, Docker images, it is recommended that you run them inside a Proxmox QEMU VM. This will give you all the advantages of application containerization, while also providing the benefits that VMs offer, such as strong isolation from the host and the ability to live-migrate, which otherwise isn’t possible with containers. ( https://pve.proxmox.com/wiki/Linux_Container )