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

I have uploaded my project on my hosting ..But when i tried to access form url I got the following Error

QueryException in Connection.php line 647:
SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: NO)

I have changed the following credentials of .env

DB_DATABASE=cpanel_database
DB_USERNAME=cpanel_db_name
DB_PASSWORD=cpanel_db_password

What could be the error for getting the Above Error?

via Chebli Mohamed