This can be done via the Business Dashboard using the Menu Editor under Online Ordering
Follow the steps given below:
1. Select Menu Editor under Online Ordering on the dashboard navigation list.
![image](https://lh3.googleusercontent.com/yDsjxlIGdXvhpuFkwpbji38JO3hFYo0CEX5jo4-icFKzDitnmcRBzE2TQ6OCSCiQzdoYpMXv4sGCbihJbFQUnR9yMJPUGFquvJmwz1HdSUjQkhJXDg_sIhvqp2WZwdfedDv2A2iE)
2. Find the Item you want to add a tax for by picking them from their relevant Category / Sub Category and select the same.
![image](https://lh3.googleusercontent.com/5wlxE7ZrRVveWjlEJxmm7F5PHjgVo9fqg3Nw879RlhTx8UueiljtUtkenReSdbCu8OvVrk0sHoV8BT_V3gx3b3C2YwxRx5na7vhIVuVtUKCsUwhHFrCm5TVLZy7zV0quYfdQl58M)
3. On selecting the Item, you will see the Item Details tab for the same, scroll down to Advanced Settings.
![image](https://lh4.googleusercontent.com/ycz9KAcKAL63OQ4sTZgeCwirVBTV8S94LqfwWyqyWDYEzJ1s0A755RoTL6WHME8N7cZP3bLTT6BVfMO5h35N7sVgjUeXVQRN_CPxnBS9EDSQK8-Ut-A-aMkJCm-6BgOBC83g3HNP)
4. From the GST dropdown list, select the relevant rate of tax.
5. Once you've made the edits click Save.