Hello ; The minimum ordering quantity for SMT assembly is 2 pieces and you can set this once you set the number of PCBs that you are willing to order and it should be less than 30 pieces. For example if you are willing to order 5 PCBs you can get them all assembled by JLCPCB or you can get only 2 PCBs assembled by JLCPCB and the three other PCBs will be delivered without assembling its parts. Please consider that the minimum number of assembled PCB is 2 pieces. Thank you for your understanding.