I am new in Infusionsoft API Integration

I want to integrate Infusionsoft API into website application for sending email to the users with existing user’s data of my application.
Please guide me step by step from beginning, how can we develop?

Thank You.

If you’re a developer, or have one who works with you, I’d recommend reading the first three sections of our REST API documentation. That’ll give you a good overview of how you should make requests to that API.

After that, have a look at the left-hand navigation of our REST API documentation to get an idea of what resources are available to you.

As you browse through the resources, be sure to expand the samples on the right (you’ll need to click Show samples).

If you’ve signed up for a developer account, you may find it useful to try out the API through the documentation. Look for the Try The API button and Try buttons, throughout.