.htaccess rewrite file path favicon.ico to core/favicon.ico

I am doing something wrong with writing my .htaccess syntax and what exactly I am unsure.

I have a file called /core/favicon.ico.

Now I want when the browser requests /favicon.ico it to have the server display: /core/favicon.ico.

The contents of my .htaccess is currently

<IfModule mod_rewrite.c>
	RewriteEngine on

	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteRule ^(.*)$ core/index.php?url=$1 [QSA,L]
	
	RewriteRule ^favicon.ico core/favicon.ico [NC,L]
</IfModule>

The previous rewrite rule is needed for the functioning of my system.

RewriteRule ^(.*)$ core/index.php?url=$1 [QSA,L]

And that rule works fine.

> RewriteCond %{REQUEST_FILENAME} !-d
> RewriteCond %{REQUEST_FILENAME} !-f
> RewriteRule ^(.*)$ core/index.php?url=$1 [QSA,L]
>
> RewriteRule ^favicon.ico core/favicon.ico [NC,L]

You've basically just got your rules in the wrong order. Presumably /favicon.ico does not exist, so the first rule rewrites the request to core/index.php?url=favicon.ico first and processing stops.

You need to reverse the two rules (and backslash-escape the dot and add the end-of-string anchor). For example:

RewriteRule ^favicon\.ico$ core/favicon.ico [NC,L]

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ core/index.php?url=$1 [QSA,L]

Aside: This does not rewrite requests for the "homepage" (the document root), so presumably you have something else that handles that? Otherwise, I would expect you need to set the DirectoryIndex accordingly at the top of the file. For example:

DirectoryIndex /core/index.php

Note that the url parameter will be absent for such requests (to the "homepage").