Craft3, Plugin Craft Commerce, Tax without percentages Is it possible to set Tax in the Rate field other than percentage?.
In Tax I want to place an example amount: 10.50 without percentages.
It's not currently possible to charge a fixed tax fee natively, it needs to be a percentage. You can however implement your own tax adjuster within a plugin or module, which is what Craft is doing under the hood.
You can specify an amount on the adjuster with a type of tax and it will then show on orders within Craft.