Use the following code in .htaccess file to remove .html from url.
This code will work for static html files.
example.com/page.html to example.com/page
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /
RewriteCond %{https://example.com} !(\.[^./]+)$
RewriteCond %{REQUEST_fileNAME} !-d
RewriteCond %{REQUEST_fileNAME} !-f
RewriteRule (.*) /$1.html [L]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([^.]+)\.html\ HTTP
RewriteRule ^([^.]+)\.html$ https://example.com/$1 [R=301,L]
</IfModule>
