Drop Down From Named Range

[Cobra17]

I'm trying to get a validation list drop down to be created from a named range in another workbook, but I'm having issues even getting it to do it from the same workbook.

It's the .Add Type line, but I'm not sure how to correct it.

Sub Test()
Dim vArray()            As Variant
Dim rng                 As Range
Dim wbk                 As Workbook

Set wbk = Excel.Application.Workbooks("Sample.xlsm") ' this will be Workbooks("Library.xlam")
Set rng = wbk.Worksheets("Sheet1").Range("Test") ' this will be wbk.Worksheets("A1").Range("Test"))
vArray = rng
    
    With ActiveSheet.Range("mm.1").Validation
        .Delete
        .Add Type:=xlValidateList, Formula1:=Join(vArray, ",")
        .IgnoreBlank = True
        .InCellDropdown = True
        .InputTitle = ""
        .ErrorTitle = ""
        .InputMessage = ""
        .ErrorMessage = ""
        .ShowInput = True
        .ShowError = True
    End With
    
End Sub