The deployment version will lag weeks/months after releases of the source code on GitHub and be announced here: https://forum.virtualmin.com/c/news/5
How to get latest Webmin before it's released to Virtualmin repos (releases are announced on https://forum.virtualmin.com/c/news/5)
A specific tested release version:
cd /tmp wget https://github.com/webmin/webmin/releases/download/2.201/webmin_2.201_all.deb apt-get install ./webmin_2.201_all.deb rm -f webmin_2.201_all.deb
A nightly untested build (not recommended for production systems):
cd /tmp wget https://download.webmin.dev/webmin-latest.deb apt-get install -y ./webmin-latest.deb rm -f webmin-latest.deb