Webpage without the .html extension issue

Hello, I recently uploaded a number of html and css files on to CPanel. I'm running into issues when trying to access other pages on my website. For example: example.com > gallery (example.com/gallery/) - I get a 403 error, my gallery page is located in the same folder as my index.html - it also doesnt recognise/can't access my .css file (exact same one used by index.html) - In my index file I have it like this:

G A L L E R Y - However, example.com/gallery.html works just fine. I have no problem loading my blog page (example.com/blog) - the .html version works fine too - I am able to load the page without .html - In my index file I have it like this:

B L O G - also noticed there isn't an extra "/" at the end of the url This is my .htcaccess file: DirectoryIndex index.html #example.com/page will display the contents of example.com/page.html RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME}.html -f RewriteRule ^(.+)$ $1.html [L,QSA] #301 from example.com/page.html to example.com/page RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\.html\ HTTP/ RewriteRule ^(.*)\.html$ /$1 [R=301,L] I would appreciate any help with this issue, I want to be able to load my gallery page without the .html extension