In this article, I posted examples for redirecting from the pages without a slash to pages with a slash.
Example 1: 301 redirect without slash to slash
RewriteCond %{REQUEST_URI} !\? RewriteCond %{REQUEST_URI} !\& RewriteCond %{REQUEST_URI} !\= RewriteCond %{REQUEST_URI} !\. RewriteCond %{REQUEST_URI} !\/$ RewriteRule ^(.*[^\/])$ /$1/ [R=301,L]
Example 2: 301 redirect without slash to slash
RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_URI} !(.*)/$ RewriteRule ^(.*[^/])$ $1/ [L,R=301]