Nextcloud

Nextcloud is a free and open-source software, used for cloud storage and collaboration tools. Piktures is NOT associated with Nextcloud.

About Nextcloud

Nextcloud is a solution allowing you to build your own personal cloud server.

Nextcloud access

Piktures is able to manage, view, upload to, and download photos from your own instance of Nextcloud, thanks to the Webdav open protocol.

You should follow the instructions provided by Nextcloud to enable WebDav access

https://docs.nextcloud.com/server/latest/user_manual/en/files/access_webdav.html