Get Oauth Authentication Token in code behind using C# in ASP.Net

Hi

I am having the setup in postman as follows: Type-OAuth2, authorization data to: Request Header, Header prefix: Bearer, Grant Type: Client Credentials, Access token url like (xxx.com/oauth2/token),

Client id-xxx and client secret - YYY and client authentication send as Auth header with this setup I am able to get access token and then using API as bearer Auth to get response. 

This setup should be in code C#. I have searched forums but haven't had clear picture with code.

Can someone please help to get access token alone from C# side with the setup above I mentioned?