Type the following in your terminal:

sudo snap install nextcloud

By default the latest stable Nextcloud snap release will be installed and it will automatically update to subsequent stable releases, but there are other releases available as well and you have full control of automatic updates.

After installation, Nextcloud will start automatically. Assuming you and the device on which it was installed are on the same network, you will reach the Nextcloud installation by visiting <hostname>.local or the IP address of the instance in your browser. If your hostname is localhost or localhost.localdomain, like on an Ubuntu Core device, nextcloud.local will be used instead.

Upon visiting the Nextcloud installation for the first time, you will be prompted to enter an admin username and password before Nextcloud is initialised. This may take a while depending on resources and the device.

After you provide that information you will be logged in and able to install apps, create users, and upload files.

See configuration and regain control over your data.