How to set up CORS (cross-origin resource sharing) in Plesk for Linux?

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How to set up cross-origin resource sharing (CORS) in Plesk to display content from example1.com on example.com?

Note: CORS is supported in the following browsers: Chrome 3+, Firefox 3.5+, Opera 12+, Safari 4+, Internet Explorer 8+

Log into Plesk UI on the source server, where domain example1.com is hosted.
Navigate to the tab Domains > example1.com > Apache and nginx settings and add the following directives to the section Additional directives for HTTP and to the section Additional directives for HTTPS:
CONFIG_TEXT: Header set Access-Control-Allow-Origin "example.com"
Check if Nginx is enabled at Plesk > Tools & Settings > Services management > nginx on the server. If static content needs to be displayed, add the following nginx directive to Domains > example1.com > Apache and nginx settings > Additional nginx directives and remove Apache directives added on step #2:

CONFIG_TEXT: add_header Access-Control-Allow-Origin "example.com";
Click Apply to save settings.