Connecting an NFC tag to a phone?

Question

NFC

Kind.
The question is: Is it possible to make contactless payments, as done in the "Wallet" application ( https://cardsmobile.ru/ ), but with an NFC tag connected externally.
The conditions are as follows:
1. There is an application on phones to manage the balance and cards. (As in the Wallet)
2. The NFC tag is connected to the smartphone using the charging port, headphones, usb.
3. The NFC tag is only responsible for the "connect" point of sale.
Thanks for the answer.

Answer 1

This is no longer a tag, but a reader.
There are very few external readers and phone models that are compatible with them out of the box.
It’s easier to attach a bank card for contactless payments to the phone.