you buy it, once it is added to your stock, it will shortly appear on you country map, then you can use the map customization to move it, no need to "deploy it, as it will automatically be function the first update after it is added to your country stock.
it will probably be purchased near the beginning of the month, assuming you aren't using immediate order, then it wont show up in the map, until the update later in that month. thats when you can move it via map customization.