Hi Im using Oauth2.0 and I am getting redirect_uri_mismatch error. However I've checked the URI and the redirect_uri I send to https://oauth2.constantcontact.com/oauth2/oauth/token is the same as what I've registered with for the API key.
I found another example of uri_mismatch : another redirect_uri issue . However the OP suggested that he needed to attach the API key to the redirect_uri. Do you know how this is done or where this is documented.
Yes, you can set or change the redirect uri value stored by us for your API Key by going to this link. You will see your API Key(s) listed after you provide your username and password. Then you can click on the API Key to change its values.
API Support Specialist