Sales Tax in Invoices Based on Buyer's Province

I am new to Dolibarr any help would be greatly appreciated. I’ve seen similar threads and can’t find any answers to this basic question.
We would like to use Dolibarr to generate invoices for customer orders.
I have setup the tax rules under setup dictonaries.
When setting up an invoice I would like the correct sales tax amount to be auto applied to each product line item based on the buyer’s province. Sales tax differs by province in Canada. By default it is leaving each line’s sales tax field blank.
Thanks for any help

option 1 : set vat rates for each province in : Dictionary setup - VAT Rates or Sales Tax Rates , and choose vat manually for each invoice line.
option 2: it is work around, if you want to vat to be auto applied based on province. add custom countries along with province ( think of each province is a new country in the world, )
option 3: if you use pre defined products and services then add each product multiple times with different code for each province and define vat in there.

thank you, For vat to be auto applied with a pre-defined product do we have to setup the same product multiple times for each province or do I just requie option 2?

If just option 2, I don’t see any way of adding a custom country. Could you reply with step by step instructions? Below is what I have in that area so far. much appreciated.

Goto Dictionary setup - Countries
add country like :
Code Label
CAAB Canada (A:sunglasses:
CAQC Canada ( QC)

you may also need language files.