Honestly my website worked fine before I even used a htaccess file. The only reason why I converted the already existing htaccess.txt to .htaccess was to make the link shorter.
A tutorial gave me the information the original joomla htaccess will hide the /index.php/ in any links.
The link is too large to share it on the game the website is focused on.
Then I used RewriteRule
^streams/(.*)/?$ /$1 [L,NC,R] to get rid of the category.
Sadly Im not able to write a htaccess file by my own.
So the link shoudlt work by using the menu and by entering the url into a browser.
Is it now more understandable?