I go to:
https://installercreator.urbackup.org/
I specify:
Server URL (with x appended), Server login & password
I put a tick:
Silent installation of client (without asking questions and without showing installation progress)
I do:
chmod +x urbackup_client_installer && sudo ./urbackup_client_installer
and … :
“Installation of UrBackup Client 2.5.25 to /usr/local … Proceed ? [Y/n]”