I am working in a WordPress theme (Divi) that needs an API key and Token to access the account. I have generated an API key and a token, however at no point did the system ask me for the account information so it can access the specific account that I need to update. If I just have a random API key and token how does it update my clients account? It seems like I should have just been able to log into the clients account and accessed this information so I could drop it into the theme.
It sounds like you were able to generate an API Key but might be confusing the Access Token with the application Secret. Usually a 3rd-party application will have its own API Key that lets the app communicate with Constant Contact, however some developers require you to provide them with your own API Key and Access Token. Since this process was designed for developers, it can be confusing for non-developers to find this information. To help de-mystify the process for everyone, we have a blog post which walks through step-by-step instructions on how to get that information. If you already have an access token, you can skip past the part that talks about creating an API Key.