I have been using PayPal to accept online payment for many years. I have used both Buy Now button and shopping cart with PayPal payment.

I set up a shopping cart on PayPal payment platform many years ago. I have been using it since then. Today, I wish to modify my website which need to change the shopping cart script too. However the interface and links structure on PayPal website have changed a lot over the years. It took me a very long time to find out what I need. In case you have the same issue as me, here’s a quick reference for you.
Where to Get the Identity Token

Payment Data Transfer allows you to receive notification of successful payments as they are made. To use this you need to get the Identity Token.

1. Log in PayPal account.

2. Go to My Account – Profile. Then click on Website Preferences link as shown in the diagram below.

3. The Website Payment Preferences screen appear. Now you can update the Return URL.

4. And the Identity Token that I spent a very long time to find.

PayPal Developer Center

If you are new to setting up shopping cart on PayPal payment platform. You can find the sample codes on PayPal website.

PayPal is a safe and free online payment solution which requires only a small transaction fee.