O84r wrote:
If you don’t mind with the following query:
for what that tax I asked in the first message exactly is? Is it as fees for any permanent purchase?
Because I know somebody who did a subscription in an app by 10 dollars and there wasn’t any tax, so when exactly will there be any taxes and is the amount constant?
A sales tax or value added tax (VAT) is required to be charged in many jurisdictions.
As this norm would seem unfamiliar to you, here is an introduction to the concept: https://en.wikipedia.org/wiki/Sales_tax
If you are familiar with sales tax or value-added tax and questioning a particular transaction, here is how Apple applies that as and when required. The following image is extracted from Payment, Financing, Refunds and VAT - Shopping Help - Apple

If you have questions about a specific purchase, contact Apple Support, as they have access to your transactions and purchases and subscriptions history, and we do not.
And entirely coincidentally having just re-read the payment link, I hadn’t realized Apple has added a limit on the number of gift cards that can be applied to a single purchase; a maximum of eight.