403 Forbidden - Apache2

I ma new to Linux and have to setup nextcloud as a project. I have installed it on Ubuntu 16.04 as a snap package. I have configured Apache according to: | https://www.linuxbabe.com/cloud-storage/setup-nextcloud-server-ubuntu-16-04-apache-mariadb-php7 | and I am still not being able to configure nextcloud.

Forbidden

You don’t have permission to access / on this server.
Apache/2.4.18 (Ubuntu) Server at #######.######.com Port 80