This is usually because of the authentication plugin of your mysql database
By default, mysql 8 default plugin is auth_socket. Applications will most times expect to log in to your database using a password.
If you have not yet already changed your mysql default authentication plugin, you can do so by:
1. Log in as root to mysql
2. Run this sql command:
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password
Replace 'password' with your root password. In case your application does not log in to your database with the root user, replace the 'root' user in the above command with the user that your application uses.