Nextcloud installation on non default path


I managed to install nextcloud on non default path.
However I get this error:

No input file specified.

whenever I go to my router ip/nextcloud.

My /var/log/lighttpd/error.log:

(mod_fastcgi.c.437) FastCGI-stderr: Unable to open primary script: /mnt/sda1/www/nextcloud/index.php (No such file or directory)

My /etc/lighttpd/conf.d/nextcloud.conf:

alias.url += ( "/nextcloud" => "/mnt/sda1/www/nextcloud" )

$HTTP["url"] =~ "^/nextcloud" {
     # Avoid possibly leaking sensitive URLs when clicking links to external resources from within nextcloud
     # This example requests that browsers always omit the Referrer header when navigating away from nextcloud
     setenv.add-response-header  += ( "Referrer-Policy" => "no-referrer")

$HTTP["url"] =~ "^/nextcloud/(build|tests|config|lib|3rdparty|templates|data)" {
     url.access-deny = ("")

Of course the file exists in /mnt/sda1/www/nextcloud/index.php