Normally this should work directly, but with some hosts it happens that the Nextcloud URL constantly has an index.php in the URL. It doesn’t have to be. So here is a quick hotfix.
Open your config.php. It is located in your nextcloud installation under config/config.php. Just add following to the config:
'htaccess.RewriteBase' => '/',
Now open your shell, go to the root of your nextcloud installation and drop following:
If you get the following as result:
bash: ./occ: Permission denied
Then occ need rights to execute. You can give occ rights with chmod:
chmod +x occ