1. Turn on GST
2. A GST rate for each item
When you add or edit an item, choose its GST rate: Same as shop (the default), No GST, 5%, 12%, 18% or 28%.
One setting is on by default: on dine-in and room service orders every item pays GST, including No GST items. Pick Up and Delivery keep No GST items tax free.
3. Extra taxes
The Taxes tab holds taxes on top of GST. Add a tax with a title, the order types it applies to (Delivery, Pick Up, Dine In), and an amount that is either a percentage or a fixed rupee amount.
You can switch a tax off without deleting it. Bills already made keep the tax they were made with.
4. Check the result
Open Settings → Bill & KOT Look and use the preview to see how the tax lines print.