Redirecting favicoin file in root directory gives a 404 error

I have added favicon.ico to root dir. There is WP installed on my site, and all the permalinks are set to have “/” trailing slash appear at the end. Now I want to achieve the same with favicon.ico.

This is the code I am using in my .htaacess but it is returning 404 error.

RewriteEngine On

RewriteCond %{REQUEST_URI} ^/favicon.ico$

RewriteRule ^(.*)$ /favicon.ico/ [L,R=301]

Any help?

Not sure why it returns such an error instead of just putting / at the end of the URL.