/**
* Add a field for attachment.
*
* @param bStatus Status upload
* @param iValue Value passed from caller
* @param szError Error uploading
*
* @return void
*/
typedef OnFileUploaded = function void (bool bStatus, any iValue, const char[] szError);

/**
* Upload file to remote host.
*
* @param szDomain URI (https://example.com)
* @param szPath Script path (upload.php)
* @param szToken Access token
* @param szFilePath File to read from
* @param szSavePath Relative path to save path
* @param szSaveFileName File name to save
* @param fCallback A function to use as a callback when the upload has finished.
* @param iValue Optional value to pass to the callback function.
*
* @return void
* @throws Error, if file doesn't exists.
*/
native void UploadFile(
const char[] szDomain,
const char[] szPath,
const char[] szToken,
const char[] szFilePath,
const char[] szSavePath = NULL_STRING,
const char[] szSaveFileName = NULL_STRING,
OnFileUploaded fCallback,
any iValue = 0
);

REST in Pawn версии не ниже 1.2.0