syncX: Easy Fulfill Tracking is able to sync the tracking info of orders that are fulfilled (with Easy Fulfill Tracking) to PayPal.
1. Navigate to https://developer.paypal.com/ and login with your Paypal account.

2. Navigate to the Live section to view Apps & Credentials.

3. In My Apps & Credentials, click on Create App.

4. In Create App, enter the App Name as syncX Easy Fulfill Tracking and click on Create App.

5. Copy the Client ID and Secret.

6. Open syncX: Easy Fulfill Tracking app and click on the Sync Tracking info to PayPal.

7. Paste the Client ID and Secret in the respective fields and click Save.

Every time the source fulfill orders, syncX: Easy Fulfill Tracking will also check if the order is present in PayPal. If the order is present, the tracking info will be updated as well.