Trying to use API functionality to integrate Dotmailer with IS. I have already set up the developer account i IS, have the API permission in Dotmailer and have the access key.
But where do I go from here?
Anybody done this and willing to help out?
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.
Thanks Tom for the info.
Apparently now all I need is a "callback URI " for the whole thing to work. Can’t find any info about this in the Help or API Docs.
Could you assist with this? Going round in circles 
It refers to part of the the OAuth2 flow, that is an endpoint running on your server to receive the tokens generated by the user’s authorization.