In Navicat for MySQL, PostgreSQL and Oracle
the error is generated because the mysql account does not have sufficient privileges to connect to the remote mysql server.
After mysql is installed, only "localhost" connections are allowed by default. Therefore, most server-side scripts can easily connect to the local database on the local server. The client computer is blocked by the remote server until user rights are configured.

If you want to access a remote mysql server from your desktop, you first need to know the permissions for the mysql system to work.
User information is stored in the user, db, host, tables_priv and columns_priv tables in the database named "mysql". The contents of these tables are read when the mysql server starts.

MySQL access control involves two stages :
1. The server checks that your desktop (host address or IP address) is allowed to connect.
2. Assuming a connection is possible, the server checks each request to see if you have sufficient permissions to execute it. For example, permission to create a table, permission to drop a table, or permission to modify a table.

The MySQL server uses the User, Db, and Host tables of the MySQL database for two-stage access control.
If your remote server supports SSH connection, your Navicat will be able to connect with remote MySQL database through SSH tunnel without any changes to existing MySQL permission settings. The main advantage of this tunneled SSH is that it allows us to connect from behind to the port of the MySQL server that is blocked by the firewall,

steps :
You can run the following command in the command prompt of the MySQL server. Check with your database administrator as they will usually have administrative rights to set permissions.
Copy the code The code is as follows:
GRANT ALL PRIVILEGES ON *.* TO 'YourUserName'@'%' IDENTIFIED BY "YourPassword";

or
copy the code as follows:
GRANT ALL PRIVILEGES ON *.* TO 'YourUserName'@'YourIP' IDENTIFIED BY "YourPassword";