Android Code Snippet Get the expiration time from firebase JWT token

Private Sub GetExpiryTime(JWTToken As String) As Long
    Dim parts() As String = Regex.Split("\.", JWTToken)
    Dim b() As Byte = UrlSafeDecodeBase64(parts(1))
    Dim s As String = BytesToString(b, 0, b.Length, "utf8")
    Dim map As Map = s.As(JSON).ToMap
    Log(map.As(JSON).ToString)
    If map.ContainsKey("exp") Then
        Dim expire As Long = map.Get("exp") * 1000
        Return expire
    End If
    Return 0
End Sub

Private Sub UrlSafeDecodeBase64 (s As String) As Byte()
    Dim jo As JavaObject
    jo.InitializeStatic("android.util.Base64")
    Return jo.RunMethod("decode", Array(s, Bit.Or(8, Bit.Or(2, 1)))) 'URL_SAFE
End Sub