Hello Nikunj,
Thank you for reaching out to Constant Contact API Developer Support. My team is here to assist outside software developers with questions about building into Constant Contact's API.
When accessing the Authorization Request URL, you have to be logged into a Constant Contact account to grant access, because you are granting access for that account.
If you are not already logged in when accessing the Authorization Request URL, and get redirected to the login page, once you log into your Constant Contact account it should direct you back to the page where you grant access to the application
Please have a look and let us know if you have any other questions!
Announcements
Join our list to be notified of new features and updates to our V3 API.
Sign Up