Access WordPress site with no trailing slash

I have an HTML website with a blog (WordPress) page under a subdirectory.

My goal here is to access pages with no trailing slash ie. *domain.com/blog*.

I’ve successfully configured to remove trailing slash for other plain HTML pages but not on the WordPress page (*/blog*). It will return an error 403 if I visit (*/blog*). If I remove .htaccess under the WordPress directory, I can visit (*/blog*) but it redirects to (/blog/) with a trailing slash.

This is my .htaccess from **root directory**:

RewriteEngine on
ErrorDocument 404 /error/error404.html

DirectorySlash Off
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI}/index.html -f
RewriteRule ^(.*)$ /$1/index.html [L]

RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI}/index.php -f
RewriteRule ^(.*)$ /$1/index.php [L]

This is the .htaccess from **Wordpress directory**:

# BEGIN WordPress
# The directives (lines) between “BEGIN WordPress” and “END WordPress” are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* – [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /blog/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

# END WordPress

Is there something wrong with my .htaccess files?

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