C# how to send a file via Telegram API

I am using WTelegramClient library.

Here is how I send messages:

var client = new WTelegram.Client(Config);
await client.LoginUserIfNeeded();
var contacts = await client.Contacts_ImportContacts(new[]
{
   new InputPhoneContact { phone = "+998901234567" } 
});

if (contacts.imported.Length > 0)
await client.SendMessageAsync(contacts.users[contacts.imported[0].user_id], "Hello, world!");

How to send multiple files? or at least one file.

I need to send files from a list or from a folder. I will be glad for any help.

List<byte[]> file = new List<byte[]>();

>Solution :

Sample from the official documentation

1.Get upload folder path, like this.

const string Filepath = @"C:\...\photo.jpg";

2.Upload file using client and path

var inputFile = await client.UploadFileAsync(Filepath);

3.Send file to peer (chats.chats[ChatId])

await client.SendMediaAsync(peer, "Here is the photo", inputFile);

Sample code

const int ChatId = 1234567890; // the chat we want
const string Filepath = @"C:\...\photo.jpg";

using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
await client.LoginUserIfNeeded();
var chats = await client.Messages_GetAllChats(null);
InputPeer peer = chats.chats[ChatId];
var inputFile = await client.UploadFileAsync(Filepath);
await client.SendMediaAsync(peer, "Here is the photo", inputFile);