Remove trailing slash wordpress website URLs

Solution:

Try these rules:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wordpress/
RewriteRule ^index\.php$ - [L]

RewriteRule ^((?!wp-admin/).+?)/$ /$1 [NC,NE,L,R=301]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
</IfModule>