Android Question Session remains open. How can be closed?

[Matt S.]

I use a server-side PHP file to connect to MySQL Database. the code is like this:

Sub Class_Globals
    Pivate Root As B4XView
    Private xui As XUI
    
    Private webClient As OkHttpClient
    Private webStream As OutputStream
    Private lastResponse As OkHttpResponse

    ...

End Sub

Private Sub LoadDataFromMySQLDatabase()
    Dim tRequest As OkHttpRequest
    tRequest = NDatabase.CreatePostRequest(<Url of the PHP File>,<parameters>)
    webClient.Execute(tRequest, 1)
End Sub

Private Sub webClient_ResponseError (Response As OkHttpResponse, Reason As String, _
        StatusCode As Int, TaskId As Int)
    Log("Web error: " & Response.ErrorResponse & " (" & StatusCode & ") " & Reason)
    Response.Release
End Sub

Private Sub webClient_ResponseSuccess (Response As OkHttpResponse, TaskId As Int)
    webStream.InitializeToBytesArray(0)
    Response.GetAsynchronously("webResponse", webStream, True, TaskId)

    lastResponse=Response
End Sub

Private Sub webResponse_StreamFinish (Success As Boolean, TaskId As Int)
    Dim arrOutput () As Byte
    arrOutput = webStream.ToBytesArray
    Dim txtOutput As String=BytesToString(arrOutput, 0, arrOutput.Length, "UTF8")
    Log (txtOutput)

    Select TaskId
        Case 1
            ... (using loaded data)
        ...
    End Select
    
    lastResponse.Release
    
End Sub

Everything is Ok except that the session remains open, and when this routine is executed more and more, a large number of open sessions violate the host service regulations.
How can I close the open session?
Another solution is to reuse the open session instead of closing it.
Does anyone have any idea of each of these?