We tested evercookie with modern desktop and mobile browsers
and found out that evercookie is still capable of using nearly all
of its original storage mechanisms. Despite, it still does not work
reliably in any of the analysed browsers and is not persistent in
private browsing mode. There are two essential reasons for this:
First, browsers do not only delete HTTP cookies and the browsing
history but also clear the cache, HSTS rules and all data stored
through web storage APIs. Second, the plugins for Flash, Silverlight
and Java are not necessary anymore, since the HTML5 standard
provides all of their functionality. By the end of 2021, Silverlight
will be the last of these plugins to reach its end of support and
thus, will limit evercookie’s abilities even more. This development,
combined with minor changes in Firefox’s default settings, would
cause evercookie to be entirely ine"ective within the reviewed
browsers.
В WP есть специальный API для отправки запросов. Под капотом оно будет само использовать то, что есть на текущей машине
читайте доку и не будет проблем
https://wp-kama.ru/id_6462/wordpress-http-api.html