This is for .htaccess of WordPress, but it can be adjusted
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
# Add trailing slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)([^/])$ /$1$2/ [L,R=301]
RewriteRule ^index.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]