using Prove.Proveapi;
using Prove.Proveapi.Models.Components;

var sdk = new ProveAPI();

V3TokenRequest req = new V3TokenRequest() {
    ClientId = "customer_id",
    ClientSecret = "secret",
    GrantType = "client_credentials",
};

var res = await sdk.V3.V3TokenRequestAsync(req);

// handle response

{
  "access_token": "eyJ...",
  "refresh_token": "eyJ...",
  "refresh_expires_in": 3600,
  "token_type": "Bearer",
  "expires_in": 3600
}