Thank you very much.
I love this manager and im utterly amazed Unraid does not have this as the default VM manager.
For those not so good at linux (like I am)
usually you can use wget to download files, but not this link.
So download the file to your computer, then use the Unraid file manager (Dynamix File Manager) to upload the file to the server from your computer. Now I dont know how to navigate to the root directories in the file manager so just put the file in some directory then go to Terminal, find the file and use the command
cp my-Virt-Manager.xml /boot/config/plugins/dockerMan/templates-user/my-Virt-Manager.xml
I dont know if you have to, but I rebooted Unraid, then go to Docker add container and virt-manager is in the template list.