Previously GST Was added via the Additional Payment Master on FitnessForce 1.0
Now on FitnessForce 2.0, you will configure your TAX directly while creating your product, This ensures the right Tax is added to the type of service provided.
In the Image below you can select the Tax Group so that GST gets added to the product automatically when you create a bill (CGST, SGST or IGST)
If you do not see GST getting added on the billing page, please check if the TAX is correctly selected for that product.
Note* This would have to be done individually for each product you sell.