Asp.Net Core - Making API calls from backend - api

Question

I have an application which is calling API's from a backend cs class, using IHostedService. With basic API calls ("http://httpbin.org/ip") it is working fine and returning the correct value, however I now need to call a Siemens API which requires me to set an Authorization header, and place "grant_type=client_credentials" in the body.
public async Task<string> GetResult()
{
string data = "";
string baseUrl = "https://<space-name>.mindsphere.io/oauth/token";
using (HttpClient client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", {ServiceCredentialID: ServiceCredentialSecret});
using (HttpResponseMessage res = await client.GetAsync(baseUrl))
{
using (HttpContent content = res.Content)
{
data = await content.ReadAsStringAsync();
}
}
}
I think I have the header set up correctly but I won't know for sure until the full request gets formatted. Is it even possible to set the the body of the request to "grant_type=client_credentials"?

Answer 1

As far as I can see from Siemens API documentation they expect Form data, so it should be like:
public async Task<string> GetResult()
{
string data = "";
string baseUrl = "https://<space-name>.mindsphere.io/oauth/token";
using (HttpClient client = new HttpClient())
{
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", {ServiceCredentialID: ServiceCredentialSecret});
var formContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair<string, string>("grant_type", "client_credentials")
});
using (HttpResponseMessage res = await client.PostAsync(baseUrl, formContent))
{
using (HttpContent content = res.Content)
{
data = await content.ReadAsStringAsync();
}
}
}
}