Declaring ActiveChart Object

Thanks for reading this, I'm still kinda of new to VBA. I'm trying to figure out how I should define ActiveChart in way similar to how I defined wk6.

I tried

Dim cht As Object
Set cht = ThisWorkbook.Worksheets("ITF_Chart").ActiveChart

Below is the code as of now with active chart highlighted in bold.

 Dim wk6 As Worksheet
    Set wk6 = ThisWorkbook.Worksheets("ITF_Chart")
       

 wk6.Columns("Q:Q").NumberFormat = "$#,##0"
    wk6.Columns("R:R").NumberFormat = "$#,##0"
    Selection.CurrentRegion.Select
    wk6.Shapes.AddChart2(201, xlColumnClustered).Select
    ActiveChart.SetSourceData Source:=Range("ITF_Chart!$N$7:$R$19")
    ActiveChart.ChartTitle.Text = "Q1 ITF"