var client = new HttpClient();
var request = new HttpRequestMessage {
    Method = HttpMethod.Get,
    RequestUri = new Uri("MyUrl"),
    Headers =
    {
        { "Authorization", "MyToken" },
        //{ "Postman-Token", "<calculated when request is sent>"},
        //{ "Host", "calculated when request is sent" },
        //{ "User-Agent", "PostmanRuntime/7.32.2" },
        { "Accept", "*/*" },
        { "Accept-Encoding", "gzip, deflate, br" },
        { "Connection", "keep-alive" },
        //{ "Content-Type", "application/json" },
    },
};
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
using (var response = await client.SendAsync(request))
{
    response.EnsureSuccessStatusCode();
    var body = await response.Content.ReadAsStringAsync();
    Console.WriteLine(body);
}

var client = new HttpClient();
var request = new HttpRequestMessage {
    Method = HttpMethod.Get,
    RequestUri = new Uri("MyUrl"),
    Headers =
    {
        { "Authorization", "MyToken" },
        //{ "Postman-Token", "<calculated when request is sent>"},
        //{ "Host", "calculated when request is sent" },
        //{ "User-Agent", "PostmanRuntime/7.32.2" },
        { "Accept", "*/*" },
        { "Accept-Encoding", "gzip, deflate, br" },
        { "Connection", "keep-alive" },
        //{ "Content-Type", "application/json" },
    },
};
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
using (var response = await client.SendAsync(request))
{
    response.EnsureSuccessStatusCode();
    var body = await response.Content.ReadAsStringAsync();
    Console.WriteLine(body);
}