Macro to Open Website with Username and Password

I got the following code off of another post but it hangs up at the username line.

Sub OpenFltPln()
    Set ie = CreateObject("InternetExplorer.application")
    ie.Visible = True
    ie.Navigate ("https://www.fltplan.com/" & ActiveCell)
    Do
        If ie.ReadyState = 4 Then
            ie.Visible = False
            Exit Do
        Else
            DoEvents
        End If
    Loop
    ie.Document.Forms(0).all("User").Value = "myusername"
    ie.Document.Forms(0).all("Password").Value = "mypassword"
    ie.Document.Forms(0).submit
    
End Sub

The website in the code is the actual website.

Thanks in advance!