In your WordPress website, go to WP-Admin > Opt-in Samurai > 3rd Party Integration
Click Activate button under ConstantContact Logo
Under the form in bottom, click on the Get Access Token Link
You will be taken to a ConstantContact Registration page (On ConstantContact website)
If you already have an account, click “I already have an account” link OR Proceed with registration
Once entered, next screen will ask your permission to Allow WP Ultimate List to access your mailing list
Click Allow
Next screen will show the access token
Copy that access token
Paste in the Access Token field on your Opt-in Samurai > 3rd Party Integration page in the form in bottom
Hit Save Changes button and you are done!