When I add this line of code into my .htaccess file my site crashes. Here's the code:

# Force trailing slash
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_METHOD} GET
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteCond %{REQUEST_FILENAME} !\.(gif|jpg|png|jpeg|css|xml|txt|js|php|scss|webp|mp3|avi|wav|mp4|mov)$ [NC]
RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1/ [L,R=301]

And here's the original .htaccess file:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase / RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

I'm trying to fix the trailing slash issue on my site.