Authorization code is malformed.

[JerryP488]

So I have a API Key and Secret with I ran in the terminal 

echo -n APPIKEY:ssecret | base64....I then put that into the Authorization header to the endpoint 

https://idfed.constantcontact.com/as/token.oauth2?code=code&redirect_uri=https://localhost&grant_typ...

in postman I set up a post to the above address with the base64 encoded API Key and secret to get the authorization key......what I get back in postman is

{"error_description":"Authorization code is malformed.","error":"invalid_grant"}

Unsure why....

[JerryP488]

ok at the point where I have an auth key however now getting message about invalid scopes.

[JerryP488 · Accepted solution]

Ok For anyone new to this using Python or another backend scripting language or (POSTMAN).......

1. Make a v3 application in your account.
2. Get the client_id(API key) and secret from this app. 
3. Find a way to base 64 the client_id:secret <<in this format together.  You'll need it.. 
4. Paste 
   https://api.cc.email/v3/idfed?client_id={{APIKEY}}&redirect_uri=https://localhost&response_type=code... 
   Into a brroowser and allow the application the {{APIKEY}} is your client_id....
   you will get a url like 
   https://localhost/?code=kasdlfakjsdlakjdfaljf09sdf0asdfu0adsfj
   You will need the above code....
5. In postman set up a call to 
   https://idfed.constantcontact.com/as/token.oauth2?code={{CODE}}t&redirect_uri=https://localhost&gran...
   Wherre the {{CODE}} is your code from step 4
   In this call you need to setup an Authorization header with the BASE64 encoded stuff from step 3.
6. Get a JSON block back with auth and refresh key and use in your backend app....