[Solved] Adobe Sign API Error: Invalid grant_type client_credentials

On Postman, I used grant type 'Client Credential' for generating access token.

But in response, I'm getting Invalid grant_type client_credentials.

Access Token URL: https://secure.na3.adobesign.com/oauth/v2/token

Though this URL works perfectly fine on grant type 'Authorization Code' if I'm using the wrong URL, do correct me.