Getting "invalid_grant" error for token/connect rest api

Hi,

I have installed Aras Innovator on Azure VM and i am trying to use REST API using Postman from my local machine but getting following error - 

400: Bad Request

{
"error": "invalid_grant"
}

Request

 'POST' : 'http://<public-ip>/InnovatorServer/oauthserver/connect/token' 

Headers-

• grant_type : "password"
• scope : "Innovator"
• client_id : "IOMApp"
• username : "admin"
• password : "607920b64fe136f9ab2389e371852af2"
• database : "InnovatorSolutions"

Please Note: I haven't changed anything in oAuth.config file.

Thanks

Vinay