Uninstall

First decommission the host in the portal (its page, Decommission): from then on the service refuses its certificate, so nothing — not even a copy of its key — can check in as it. Then remove the agent.

Installed from the repository

sudo apt-get remove updawg-agent     # Debian, Ubuntu: keeps /etc/updawg and /var/lib/updawg
sudo apt-get purge updawg-agent      # …and removes them, identity included
sudo rm /etc/apt/sources.list.d/updawg.list /etc/apt/keyrings/updawg.asc

sudo dnf remove updawg-agent         # RHEL family, Amazon Linux
sudo rm -rf /var/lib/updawg /etc/updawg /etc/yum.repos.d/updawg.repo

Removing stops and disables the service. A removal keeps the host’s identity, so reinstalling needs no new enrolment; purging (or deleting /var/lib/updawg) does not.

Installed without a package manager

The static binaries, or an agent an earlier one-liner put in /usr/local/bin:

sudo systemctl disable --now updawgd.service
sudo rm /etc/systemd/system/updawgd.service /usr/local/bin/updawgd /usr/local/bin/updawgctl
sudo systemctl daemon-reload
sudo rm -rf /var/lib/updawg /etc/updawg