Trying to execute Adobe Sign APIs, it is throwing error.

[Kalyani Wani]

I'm trying to execute Adobe Sign APIs, but it is throwing the following error -

{

    "code": "PERMISSION_DENIED",

    "message": "The API caller does not have the permission to execute this operation"

}

Please note that I'm using the Trial developer account of Adobe Sign.

I'm able to generate Access Token as well for the Authentication purpose but I'm not able to use any of the other APIs.

To generate access token I'm using following URL - 

https://api.echosign.com/oauth/v2/token

Headers -

code:{code}
client_id:{clientid}
client_secret:{clientsecret}
redirect_uri:https://www.google.co.in
grant_type:authorization_code

Can someone help?