How to create a PayPal App:
Step 1: Log into PayPal Dashboard
Click here (https://developer.paypal.com/developer/applications/) to log in to the PayPal Developer site.
(If you do not have a PayPal account, then create one first here. (https://www.paypal.com/in/webapps/mpp/account-selection?pros=2).
Step 2: Click on My Apps & Credentials under the Dashboard menu.
Step 3: Scroll down to the "REST API apps" section & Click on "Create App".
Step 4: Add an App Name, select a sandbox account from Sandbox Business Account, and then click on Create App.
Step 5: As your new app is created, you will see the Client ID and the Secret Key. Copy & save the keys for your app.
How to Connect to PayPal:
Step 1: Login to your TrackFree account
Step 2: Click on “Settings” from the top menu in the TrackFree admin panel.
Step 3: Click on the “Connect” button under the PayPal Auto Update option. A popup window is opened.
Step 4: Enter your PayPal App Email, Client ID & Secret key. (Sandbox mode is optional ).
Step 5: After entering the details, click on “Connect”.