StackingItem shop support - Ghost-chu/QuickShop-Reremake GitHub Wiki
QuickShop allows users to sell/buy more than one item per transaction. But it is not enabled by default. You need to turn on it in configuration.
Configuration
allow-stacks: true
Make it work
/qs reload
to make changes works.
NOTICE: Player requires permission to create stacks item shop, check them in the permission list.