Nextcloud/index.php does not run

Hi all,
after a new install of Nextcloud on Raspberry (now I can see lighttpd is installed instead apache2, isn’t it?), if I type nameofthehost/nextcloud/index.php instead of seeing the login page I see the index.php list as the same ones appearing with notepad. Why? Is there anything to install later? Sorry for the elementary question! :thinking:
Thanks for your help.