Can't access phpMyAdmin - Error

I can’t access my phpMyAdmin.

Error: phpMyAdmin - Error
Error during session start; please check your PHP and/or webserver log file and configure your PHP installation properly. Also ensure that cookies are enabled in your browser.

session_start(): open(SESSION_FILE, O_RDWR) failed: No space left on device (28)

session_start(): Failed to read session data: files (path: /var/lib/lsphp/session/lsphp74)

OS: ubuntu 20.04
CP Version:
Current Version: 2.3
Build: 4

How to fix?