Xojo.Net.HTTPSocket is returning the file (supposedly). The file size saved to disk is 62 bytes. The actual file size is 4.69Mb. I tried URLConnection as you suggested and get the same “There is more than on method…” error at compile time.
Dim fileID As String = "4_z642f713eb97d25bb7b340510_f111bf2b54be92c40_d20200911_m230002_c000_v0001074_t0024"
Dim requestURL As String = auth.apiUrl + "/b2api/v2/b2_download_file_by_id" + "?fileId=" + fileID
Dim f As new Xojo.IO.FolderItem(App.DocumentRoot.ToText)
f = f.Child("pic.jpg")
'myHTTPSocket1.Send("GET", requestURL.ToText, f)
FileDownloader.Send("GET", requestURL, f)