authorization.server.deprecated

Running v5.3.2

Set up the integration on constantcontact following these instructions – https://contactform7.com/constant-contact-integration/

Clicking the ‘Connect to the Constant Contact API’ button results in this error:

[{“error_key”:”authorization.server.deprecated”,”error_message”:”This authorization url is no longer supported. Please update your application and send any further authorization requests to https://authz.constantcontact.com/oauth2/default/v1/authorize.”}]

Can anyone please assist?