ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[Marina Levy]

Hello,
I can't login with command "mysql" on Ubuntu 18.04.
I've checked the SSL(curl --verbose https://live.cardeasexml.com/ultradns.php) and got "SSL certificate verify ok".
Than I've checked in mysql:

mysql> SHOW VARIABLES LIKE '%SSL%';
+---------------+-----------------+
| Variable_name | Value |
+---------------+-----------------+
| have_openssl | YES |
| have_ssl | YES |
| ssl_ca | ca.pem |
| ssl_capath | |
| ssl_cert | server-cert.pem |
| ssl_cipher | |
| ssl_crl | |
| ssl_crlpath | |
| ssl_key | server-key.pem |
+---------------+-----------------+
9 rows in set (0.01 sec)

mysql> status

Connection id: 7
Current database:
Current user: root@localhost
SSL: Cipher in use is ECDHE-RSA-AES128-GCM-SHA256
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server version: 5.7.33-0ubuntu0.18.04.1 (Ubuntu)
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP
Server characterset: latin1
Db characterset: latin1
Client characterset: utf8
Conn. characterset: utf8
TCP port: 3306
Uptime: 44 min 35 sec



and still I can't login in mysql.
What should I do?
Thank you in advance,
Marina