/roundcubemail/installer path to start the installation process.
/etc/httpd/conf.d/roundcubemail.conf file to provide access to /roundcubemail/installer directory for everyone.
<Directory /usr/share/roundcubemail/installer/> <IfModule mod_authz_core.c> Require granted all # Require local <-- remove this.
You need to put Require granted all in place of Require local and reload the http server.
/etc/roundcubemail directory for it to work. Yes the horror, a folder in your /etc directory has to be given world write permission otherwise it won't work. Later you can revoke it.
/etc/roundcubemail/config.inc.php and add this line
$config['smtp_server'] = 'tls://sanjir.com';
For it to work with TLS.
/etc/roundcubemail/config.inc.php file too. See that it's in the root. Change it to some sane location. And it will initialize after installation.
/etc/roundcubemail/config.inc.php and then try again.
chown -R habib.habib /etc/roundcubemail/. And no other directory from the roundcube installation will need permission change other than this one.