Add Trailing Slash .htaccess

Please add below lines top of .htaccess file

RewriteEngine on
#Add Trailing slash for end of the URL
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*[^/])$ /$1/ [L,R]

RewriteCond %{REQUEST_URI} !(/$|\.) 
RewriteRule (.*) %{REQUEST_URI}/ [R=301,L] 

This code needs to be put at the top of your .htaccess file below RewriteEngine On