Square Client to Obtain Token

[espo4life]

@Bryan-Square

var body = new ObtainTokenRequest.Builder(
        "APPLICATION_ID",
        "APPLICATION_SECRET",
        "authorization_code")
    .Code("CODE_FROM_AUTHORIZE")
    .Build();

try
{
    ObtainTokenResponse result = await oAuthApi.ObtainTokenAsync(body);
}
catch (ApiException e){};

My question is more how do I instantiate oAuthApi? I am use to doing the following

                var client = new SquareClient.Builder()
                      .Environment(Square.Environment.Production)
                      .AccessToken(access_token)
                      .Build();

                IOAuthApi oAuthApi = client.OAuthApi;

but if I dont have an access token, what do I do?