Find Primary Key With ADO

I have a connection to an Access DB with ADO.
How can I get the Primary Key name field with ADO ?

here ya go

Code:

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    Dim cn As ADODB.Connection
    Dim ax As ADOX.Catalog
    Dim tbl As ADOX.Table
    Dim ky As ADOX.Key
       
    Set cn = New Connection
   
    cn.Open "Provider=Microsoft.JET.OLEDB.4.0;Data Source=Nwind.mdb"
   
    Set ax = New Catalog
   
    ax.ActiveConnection = cn
   
    Set tbl = ax.Tables("Customers")
   
    For Each ky In tbl.Keys
        MsgBox ky.Type  'returns KeyTypeEnum
    Next ky
   
    'cleanup.....

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