.htaccess file does not work

Hello! I wanted to say, that you have best free host out there!
I love it!.

And now, to the point. I used to store my website, just small html/css/js for school project, on 000webhost, where I uploaded this .htaccess file to rewrite .html endings from url.

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)\\.html$ /$1 [L,R=301] 

When I do it here ( I created my own .htaccess not edited your premade ), it did not work, and it wasnt redirecting me to page, lets say domain.com/dogs, but to error page of infinityfree. Any advice?