The taxes and shipping options displayed in the app are determined by Shopify. To accurately calculate taxes and display available shipping options, Shopify requires the shipping address of the quote recipient. This information can be configured in two ways.
Shopify Customer:
On the quote detail page, there is an option to assign a Shopify Customer. Clicking this option will allow you to search your Shopify store for an existing customer. If the selected customer has a default address, Shopify will use this address to calculate the taxes and display the available shipping options
Note: There is also an option in the app settings that will create a new customer in Shopify and assign the customer to the quote automatically when the quote is requested.
Shipping Address Custom Field
If you include an address field with the type "Shipping Address" in your quote request form, then Shopify will use this address to calculate the taxes and display the available shipping options.
Address fields can be added to the quote request page through the Custom Fields page in the app.