qemu macos host ubuntu client copy and paste not working

i started an already installed qcow2 image as in https://www.arthurkoziel.com/qemu-ubuntu-20-04/. macos 11.0 host and ubuntu 2004 client. Everything works fine. But i also need copy and paste throw vm and host. So i did an apt-get install qemu-guest-agent as descripted in https://pve.proxmox.com/wiki/Qemu-guest-agent But the systemctl start qemu-guest-agent failed because of a dependency job for qemu-guest-agent.service failed So what was going wrong? How can i enable copy and paste?