What are Entity tags (Etags) and how do you configure them in relation to your Drupal site's files? The GTmetrix Page speed &amp; optimization test notified me that 13 components in my site (all are files) have &quot;misconfigured Etags&quot;, so I ran a search query like &quot; Drupal Entity tags &quot; in Google and found almost nothing that was instructive for me (for my knowledge and understanding) on how to solve it via the Drupal UI. Therefore my question is first of all what are these Etags (or Entity tags) and how can I add them (or just configure them right, if they exist), For the relevant files?
Much thanks,
https://en.wikipedia.org/wiki/HTTP_ETag

Inside your .htaccess file add this to the bottom
FileETag MTime Size