Showing an xlam userform in an xlsm - excel

Question

I have a form in an xlam. I would like the form to be usable in an xlsm.
With the help of ThunderFrame's link, I think I am close, but have no idea where to go from here.
I followed the steps in https://stackoverflow.com/questions/45231935/userform-in-excel-sheet-can-it-be-made-an-add-in, but get error "Compiler error: Method or data member not found" when I add code to a toggle button. I tried adding the GetUserForm function in the xlam's form code, which failed, then in an xlsm's module, which failed. Here is my code:
Public Function GetUserForm() As frmQuickQuote
Set GetUserForm = New frmQuickQuote
End Function
Here is my toggle button code:
Private Sub tglQQ_Click()
Dim frm As PRI_Comp_Life.frmQuickQuote
If tglQQ Then
tglQQ.BackColor = lngPressed
Set frm = PRI_Comp_Life.GetUserForm()
frm.Show
Else
tglQQ.BackColor = lngUnPressed
Unload frmQuickQuote
End If
End Sub
I was expecting the form to load when I pressed the toggle button tglQQ, and unload when I pressed it again. Thanks.
EDIT: form now showing, but getting an error "Method 'Range' of object '_Global' failed" when the form loads. Form code:
Private Sub cmdReset_Click()
Dim MyLoop As Integer
'Set defaults
Me.cboRepLevel = Range("rngDefaultContract") 'errors here
With Me.cboAge
For MyLoop = 18 To 70
.AddItem MyLoop
Next MyLoop
End With
End Sub

Answer 1

This works for me.
In the ThisWorkbook module of the add-in
Public Function GetForm() As Object
Dim frm As frmTest
Set frm = New frmTest 'a form in the add-in
Set GetForm = frm
End Function
Button code:
Private Sub ToggleButton1_Click()
Dim addin As Object
Static frm As Object
If ToggleButton1.Value Then
Set addin = Workbooks("test.xlam")
Set frm = addin.getform()
frm.Show vbModeless
Else
Unload frm
End If
End Sub
Note it's all very late-bound.