Use Magento Out-Of-Box tax

OOB tax setup for testing:

Magento 2 has useful Out-of-box (OOB) product tax and shipping tax (ship tax) features. This guide shows how to set them up.
Remember to disable third-party tax modules, such as Avatax

Step 1: Stores > Tax Zones and Rates : setup a tax zone e.g. CA or WA, wildcard / * for zip, tax rate e.g. 8.25%

Notice naming conventions, product tax is `IL_625`, ship tax is `ship_IL_6265`

Step 2: Add two tax rules, one for Product Tax and one for Ship Tax:

Step 2a: Rule one: Product Taxes:

Step 2b: Rule two: Shipping taxes

Notice, in Shipping_Taxes rule, in the ProductTaxClass, add a new class and name it `shipping_tax`shipping_tax`

Step 3: Configure tax classes and rules
3a: Configure Ship Tax class as the `shipping_tax` class we created above

3b: Configure Shipping Tax Price Calculation as `Including Tax`:

 

That's it.