How to call macro after Refresh or Refresh All button pressed?

You haven't actually connected the querytable to the class instance. Revised qtclass

Option Explicit

Private WithEvents qt As Excel.QueryTable
Public Property Set HookedTable(q As Excel.QueryTable)
    Set qt = q
End Property

Private Sub qt_AfterRefresh(ByVal Success As Boolean)

    MsgBox "qt_AfterRefresh called sucessfully."
    If Success = True Then
        Call Module2.SlicePivTbl
        MsgBox "If called succesfully."
    End If

End Sub

Private Sub qt_BeforeRefresh(Cancel As Boolean)
    MsgBox "qt_BeforeRefresh called."
End Sub

New ThisWorkbook code:

Dim qtevent As qtclass
Private Sub Workbook_Open()

    Set qtevent = New qtclass
    Set qtevent.HookedTable = ThisWorkbook.Worksheets("Data-Fund").ListObjects(1).QueryTable

End Sub

Note that this is quite closely coupled. It would be more re-usable if you were to raise events in the class and declare your qtevent variable WithEvents.

Source: https://www.excelandaccess.com/create-beforeafter-query-update-events/

Class: Note: Class Name = clsQuery

Option Explicit

Public WithEvents MyQuery As QueryTable

Private Sub MyQuery_AfterRefresh(ByVal Success As Boolean)
 If Success Then
  Debug.Print "After ReFresh"
 End If
End Sub

Private Sub MyQuery_BeforeRefresh(Cancel As Boolean)
 Debug.Print "Before ReFresh"
End Sub

Module:

Option Explicit
Dim colQueries As New Collection
Sub InitializeQueries()

Dim clsQ As clsQuery
Dim WS As Worksheet
Dim QT As QueryTable

For Each WS In ThisWorkbook.Worksheets
 For Each QT In WS.QueryTables
  Set clsQ = New clsQuery
  Set clsQ.MyQuery = QT
  colQueries.Add clsQ
 Next QT
Next WS

End Sub

ThisWorkbook.Event:

Private Sub Workbook_Open()
 
 Call InitializeQueries
 
End Sub