Authentication works without any problem. But the token expires and when it tries to fetch the refresh token it gives the error message "Invalid grant_type refresh_token".
After debugging, I found that to refresh the token, the url is 'https://secure.in1.echosign.com/oauth/refresh'
The application has 2 URLs
- access token url: https://secure.in1.echosign.com/oauth/token
- refresh token url: https://secure.in1.echosign.com/oauth/refresh