Calendar and contacts
The English version governs if the two differ.
iPhone and iPad
Settings → Apps → Calendar → Accounts → Add Account → Other → Add CalDAV Account. Repeat under Contacts with Add CardDAV Account.
Server cloud.totuldigital.ro Username your full address, e.g. ana@example.com Password a device password, not your account password
Thunderbird, Android and everything else
Android needs DAVx⁵ from the Play Store or F-Droid; Android has no built-in CalDAV. Thunderbird supports CalDAV directly. Both can discover the accounts from the base address.
Base URL https://cloud.totuldigital.ro Calendars https://cloud.totuldigital.ro/dav/cal/<your address>/ Contacts https://cloud.totuldigital.ro/dav/card/<your address>/
A calendar you create in the browser appears on the phone, and an event created on the phone appears in the browser. It is one calendar, not a copy.