Why don't RewriteRule work in Joomla?

Question

Apache HTTP Server

There is a task to set up CNC for SEO in Joomla! 3.8
You need to remove all .html in the URL, also / at the end
Google similar solutions:

RewriteCond %{REQUEST_URI} (.*/[^/.]+)($|\?)
RewriteRule .* %1/ [R=301,L]
RewriteRule (.*)\.html$ $1 [R=301,L]
RewriteRule (.+)\.html?$ https://site.ru$1 [R=301,L]

Only works:

REDIRECTMATCH 301 ^(.*)\.html$ https://site.ru$1
REDIRECTMATCH 301 ^(.+)/$ https://site.ru$1

But at the same time, the main one (404) does not work, because a redirect is being performed (xs why) from site.ru to site.ru/index I realized
that for some reason they do not work (not strong in htaccess)
The code of all .htaccess is here https: //pastebin.com/dJHRkUSC

Answer 1

spoiler

##
# @package  Joomla
# @copyright    Copyright (C) 2005 - 2012 Open Source Matters. All rights reserved.
# @license  GNU General Public License version 2 or later; see LICENSE.txt
##

##
# READ THIS COMPLETELY IF YOU CHOOSE TO USE THIS FILE!
#
# The line just below this section: 'Options +FollowSymLinks' may cause problems
# with some server configurations. It is required for use of mod_rewrite, but may already
# be set by your server administrator in a way that dissallows changing it in
# your .htaccess file. If using it causes your server to error out, comment it out (add # to
# beginning of line), reload your site in your browser and test your sef url's. If they work,
# it has been set by your server administrator and you do not need it set here.
##

## Can be commented out if causes errors, see notes above.
Options +FollowSymLinks


<ifModule mod_expires.c>
ExpiresActive On
#по умолчанию кеш в 5 секунд
ExpiresDefault "access plus 5 seconds"
#кэшировать флэш и изображени¤ на мес¤ц
ExpiresByType image/x-icon "access plus 2592000 seconds"
ExpiresByType image/jpeg "access plus 2592000 seconds"
ExpiresByType image/png "access plus 2592000 seconds"
ExpiresByType image/gif "access plus 2592000 seconds"
ExpiresByType application/x-shockwave-flash "access plus 2592000 seconds"
#кэшировать css, javascript и текстовые файлы на одну неделю
ExpiresByType text/css "access plus 604800 seconds"
ExpiresByType text/javascript "access plus 604800 seconds"
ExpiresByType application/javascript "access plus 604800 seconds"
ExpiresByType application/x-javascript "access plus 604800 seconds"
#кэшировать html и htm файлы на один день
ExpiresByType text/html "access plus 43200 seconds"
#кэшировать xml файлы на дес¤ть минут
ExpiresByType application/xhtml+xml "access plus 600 seconds"
</ifModule>

## Mod_rewrite in use.

RewriteEngine On

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index\.(php|html?)\ HTTP/
RewriteRule ^(.*)index\.(php|html?)$ https://site.ru/$1 [R=301,L]

RewriteRule ^(.*)\.html?$ https://site.ru/$1 [R=301,L]

RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ https://site.ru/$1 [R=301,L]

RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]


## Begin - Rewrite rules to block out some common exploits.
# If you experience problems on your site block out the operations listed below
# This attempts to block the most common type of exploit `attempts` to Joomla!
#
# Block out any script trying to base64_encode data within the URL.
RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR]
# Block out any script that includes a <script> tag in URL.
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
# Block out any script trying to set a PHP GLOBALS variable via URL.
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
# Block out any script trying to modify a _REQUEST variable via URL.
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})
# Return 403 Forbidden header and show the content of the root homepage
RewriteRule .* index.php [F]
#
## End - Rewrite rules to block out some common exploits.

## Begin - Custom redirects
#
#
## End - Custom redirects

##
# Uncomment following line if your webserver's URL
# is not directly related to physical file paths.
# Update Your Joomla! Directory (just / for root).
##

# RewriteBase /

## Begin - Joomla! core SEF Section.
#
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
#
# If the requested path and file is not /index.php and the request
# has not already been internally rewritten to the index.php script
RewriteCond %{REQUEST_URI} !^/index\.php
# and the request is for something within the component folder,
# or for the site root, or for an extensionless URL, or the
# requested URL ends with one of the listed extensions
RewriteCond %{REQUEST_URI} /component/|(/[^.]*|\.(php|html?|feed|pdf|vcf|raw))$ [NC]
# and the requested path and file doesn't directly match a physical file
RewriteCond %{REQUEST_FILENAME} !-f
# and the requested path and file doesn't directly match a physical folder
RewriteCond %{REQUEST_FILENAME} !-d
# internally rewrite the request to the index.php script
RewriteRule .* index.php [L]
#
## End - Joomla! core SEF Section.

Answer 2

First you need to uncomment line 76 # RewriteBase /

Answer 3

A simple CNC system in Joomla is configured in the General settings and for this you do not need to touch .htaccess , it is better to take it from the archive with pure Joomla (it is there in the form of htaccess.txt)
You can manage SEF links (including a slash at the end of the url) also with the help of third-party extensions (JoomSEF, sh404SEF, etc.) - and also through the admin panel, without touching .htaccess.
If you do not have third-party extensions for managing SEF, then to remove .html extensions from URLs, just open General settings in the admin panel and:
Remove the slash from the end of the URL - try using .htacess like this:
RewriteCond %{REQUEST_FILENAME} !- d
RewriteCond %{REQUEST_URI} (.+)/$
RewriteRule ^ %1 [R=301,L]