Auto-Key's "Send to Auto-Tune" button is designed to automatically transmit Auto-Key's detected Key and Scale setting to every instance of Auto-Tune Pro in your session.  In the event that you find Auto-Tune Pro's Key and Scale settings do not update to match Auto-Key's after pressing the "Send to Auto-Tune" button, there are a couple things you can try to resolve the issue:


Make sure Auto-Tune Pro's "Enable Auto-Key Key/Scale Detection" setting is enabled:

1. Open Auto-Tune Pro, click on the Settings drop-down menu, and click on Preferences. 


2. Make sure that the "Enable Auto-Key Key/Scale Detection" setting is enabled (checked).  If you don't see a check mark next to it, click on it to enable this setting.


3. Make sure the "Save as Default" check box is checked.


4. Click "Save" to save your settings.


Once Auto-Tune Pro's "Enable Auto-Key Key/Scale Detection" setting is enabled, Auto-Key's "Send to Auto-Tune" button should work as expected.


Repair Disk Permissions (Mac only):

If you followed the above instructions to ensure that the "Enable Auto-Key Key/Scale Detection" setting is enabled in Auto-Tune Pro, but are finding that pressing Auto-Key's "Send to Auto-Tune" button still does not update Auto-Tune Pro's Key and Scale settings, repairing your Mac's disk permissions should resolve the issue.  On a Mac you can do this by opening up the Disk Utility application.  Then select your main system hard drive that your applications are installed on and click on the "First Aid" button.  (If you're on an older Mac OS prior to OS X 10.11.6, you can select the "Repair Disk Permissions" option in Disk Utility instead).