Installation or missing access rights

[Jackobli]

Sorry, again.
I installed the plugin and activated it on my theme's page.php
The form loads, but throws an error:

hCaptcha has failed to initialize. Please see the developer tools console for more information

error_log tells my, that a folder/file "bl-content/easyComments/sitekey.txt" is missing/could not be opened.
There was no such directory so I created it, but what about the file sitekey.,txt?

Regards, Urs