Constant Contact wants to help you succeed! We’re celebrating our professional service programs on the Constant Contact Community this month and you have a chance to try one of the services for free! Learn more.
We have written an article with step by step instructions on how to get those pieces of information. Please follow this link and go through the steps listed.
It looks like the link had an extra space at the end. I have fixed it. Please try again. For convenience, the URL is https://community.constantcontact.com/t5/Product-News/How-to-generate-an-API-Key-and-Access-Token/ba...
This does contain the steps needed for getting this information.
Tier II API Support Engineer