The templates will automatically show any taxes calculated by Shopify.
If you don't see any taxes on your invoice, we recommend double-checking your tax settings in the Shopify admin. You can do that on this page:
https://shopify.com/admin/settings/taxes
Once taxes are set up in the Shopify admin, they will automatically display during checkout, in emails, and on invoices.
Note: Shopify will not update old orders when you make tax changes, so only new orders will show the new taxes you have set up.