Android does not have built-in support for CalDAV synchronization. To synchronize the Calendar, install on your smartphone an application that uses system calendars and can work with the CalDAV protocol, for example CalDAV-Sync.
1 Open your smartphone’s settings.
2 Select Accounts and sync (Accounts and sync).
3 Click Add Account.
4 Select CalDAV.
5 Specify account settings:
Server name: caldav.yandex.ru:443
Use SSL: yes
User name: your email@example.com
Password: your password (or application password if you enabled two-factor authentication)
Save your settings.