It so happens that you need to quickly change the user's password, and there is no control panel on the server. In this case, you can use the console command, which must be executed as root on the mysql server.
mysql> SET PASSWORD FOR 'username' @ 'hostname' = PASSWORD (' newPassWord ');
username is the name of the database user.
hostname - domain, as a rule, localhost or IP 127.0.0.1
newPassWord - replace with a new password.
The password can use letters, numbers and some special characters: @, #, _. Also, for security reasons, the password does not have to match the username.