Error with listbox . additem

I have a userform ("Userform1") and I am trying to add two items to a listbox.

When the code runs the line

.AddItem = "Acquisition Budget"

I get an error "Compile error: Expected Function or variable". Code below. Any ideas?

Private Sub UserForm_Initialize()
    
Dim MySheet As String

    TextBox3.Value = 0
    TextBox4.Value = 0

    MySheet = "Data Validation"

    
    ListBox1.RowSource = "'" & Sheets(MySheet).Name & "'!" & Sheets(MySheet).Range("Building[Building]").Address
    
    With UserForm1.ListBox2
        .AddItem = "Acquisition Budget"
        .AddItem = "Original Budget"
    End With


    
    
End Sub