Demo site "Online JSON API client" does not work again, since the server does not give permission for CORS

[NadiyaDyka]

Open the page: http://ngx-jsonapi.reyesoft.com/#/authors in Firefox, open the Developer Tool, refresh the page.

Expected Result: a working "ngx-jsonapi example" is available on the page. The page displays a list of authors.
Actual result: a message "No connection 2!!!" is displayed next to the "ngx-jsonapi example" title. No data is displayed.

There is a blocked request in the list of requests in the Developer Tool :
Method: OPTIONS, URL: http://jsonapiplayground.reyesoft.com/v2/authors?sort=name&include=books
Transferred: CORS Missing Allow Origin

Presumably, the server should give permission for CORS.