Nextcloud server doesn't work after ip change

Hello I’m a newbie in Ubuntu and Nextcloud. So I’ve instaled Nextcloud on my laptop on an Ubuntu 16.04 it worked. But the IP is not static. After that I closed my computer. Next day I started my computer I use ifconfig to find the IP address and inserted in /etc/apache2/sites-available/nextcloud.conf and restarted the apache service. When I try nexcloud it just gives me a blank page from index.php.
Can you help me please?