You cannot add "Cisco Business 350 Series 350-8FP-2G - Switch - L3 - Managed - 8 x 10/100/1000 (PoE+) + 2 x combo Gigabit Ethernet/Gigabit SFP - rack-mountable - PoE+ (120 W)" to the basket because the product is out of stock.
Cisco – Network stacking module (pack of 2) – for Catalyst 9200L