Hello, i have a fresh install done by composer and your instructions on the my licenses page. I have pro version - but the same problem was with community.

I have:

php file with setup - i am sure, everything is ok here.

view file:

...
   ColumnChart::create(array(
        "dataSource"=>$this->src('mc')->query("
        SELECT 
                                    p.displayName as displayName, 
                                    sum(1) as uzycie
                                FROM oldLogs l 
                                    left join users_field_data u on u.uid = l.userId 
                                    left join processesList p on p.pid = l.processesListId
                                GROUP BY 1
            ")
        ));
...

index.php

<?php
require_once "SalesByCustomer.php";

$salesByCustomer = new SalesByCustomer();
$salesByCustomer->run()->render();

But i get those errors in client (Chrome latest):

Refused to execute script from 'http://****.pl/reports/vendor/koolreport/core/src/clients/core/KoolReport.js' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.
index.php:14 Uncaught ReferenceError: KoolReport is not defined
    at index.php:14
(anonymous) @ index.php:14
index.php:30 Uncaught ReferenceError: KoolReport is not defined
    at index.php:30
(anonymous) @ index.php:30
index.php:44 Uncaught ReferenceError: KoolReport is not defined
    at index.php:44
(anonymous) @ index.php:44

No errors in PHP.

PHP 7.2.19

Maybe i miss something on server side, some library needed?

Ok found the solution by myself.

The problem was in the server configuration. Drupal adds very strict rules for mod_rewrite and content protection to all subdirectories.

Just added the .htaccess file and turned off some of Drupal configurations. Works now.