That's a specific question about the application and the plugins/themes you use. Could you please contact the developers of the plugin that is returning that error message so you get more information from them? By the way, there are other WordPress plugins that help you configure those headers in the app
Please note that if the plugin uses the .htaccess files to set any configuration parameters, you will need to migrate that info to the main htaccess.conf file for the changes to take effect.
Happy to help!
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