Yeah, caught you too late... It is very simple:
You just install RoundCube into the /etc/sentora/panel/etc/apps/webmail/ folder, then edit the config.inc.php with your root db login info and roundcube database name.
You just install RoundCube into the /etc/sentora/panel/etc/apps/webmail/ folder, then edit the config.inc.php with your root db login info and roundcube database name.