I want to detect live streaming m3u8

Imports System.Net
Imports System.Text.RegularExpressions

Public Class Form1

    Private Sub btbClick_Click(sender As Object, e As EventArgs) Handles btbClick.Click

        Dim textUrl As String = txtURL.Text

        Try
            Dim webClients As New WebClient()

            Dim pageContents As String = webClients.DownloadString(textUrl)
            LabelT.Text = "Page content fetched successfull."

            Dim patTerns As String = "(http[s]?://[^\s]*\.m3u8)"
            Dim reGexs As New Regex(patTerns, RegexOptions.IgnoreCase)
            Dim matChes As MatchCollection = reGexs.Matches(pageContents)

            If matChes.Count > 0 Then
                LabelT.Text = ".m3u8 links found."

                For Each matchs As Match In matChes
                    lstOut.Items.Add(matchs.Value)
                Next
            Else
                LabelT.Text = ".m3u8 links not found."
            End If

        Catch ex As Exception
            LabelT.Text = "Error fetching or processing page content:" & ex.Message
        End Try

    End Sub

End Class