If you are using DualShield Server 8.0 or later, after registering the API agent, you need to assign the "API Agent"  role to the agent:

1. Click the context menu of the new agent
2. Select "Roles"
3. Select "API Agent", the click "Save" button to close the dialog.

The default permission of the role is defined as:

You may modify it as needed. If necessary, you can also create a custom role and assign it to the agent to achieve more granular permission control.