How to properly upload textolite to the site?

Question

HTML

There is a landing page on the host, I need a mini cms for editing texts, I uploaded textolite, everything is ok on my host, it doesn’t work on the customer’s host!
I follow the link name-site.ru/textolite, writes 403 Forbidden and nginx/1.12.2, they say there is no access, add another name-site.ru /textolite/textolite.php , log in and then again writes 403 Forbidden and nginx/1.12 .2