I have a blue screen after installing in my URL http://XXXX/osticket/scp/login.php

I've installing osTicket-1.15.2-Awesome-101 over osTicket (v1.15.2) in Debian 10.
PHP v7.3.29 || MySql 10.3.29-MariaDB

I followed every indicated step an verify the ost-config.php file every times.

From php log error:

[Tue Sep 28 13:01:33.053409 2021] [php7:error] [pid 14304] [client XXXX:42518] PHP Fatal error: require_once(): Failed opening required '/var/www/html/osticket//osta/php/functions.php' (include_path='./:/var/www/osticket/include/:/var/www/osticket/include/pear/') in /var/www/osticket/include/staff/login.tpl.php on line 5

Could anyone help me?

Thanks!