How to allow slash and other characters at the end of URL in htaccess file?

Question

htaccess

Good afternoon! I can't get over the slash at the end of the URL. All pages are written in php
The site easily opens at domen.ru/page.php and domen.ru/page
But when you try to access the link domen.ru/page/ gives "Not Found The requested URL was not found on this server."
There were also problems with passing GET parameters. If you pass it through the form, then the variable is passed, but if you manually write the query domain.ru/page/?id=2 into the address bar, then again "Not Found The requested URL was not found on this server."

My htaccess:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]

Answer 1

RewriteEngine On
RewriteCond %{REQUEST_URI} ^(.*/[^/\.]+)$
RewriteRule ^(.*)$ http://%{HTTP_HOST}/$1/ [R=301,L]

if the site is with https, then change accordingly