My iPhone doesn't have the "add cellular tariff", when I try to scan the QR code

Hello! I don't have the "add cellular tariff" item, when I try to scan the qr code, I get the inscription "cellular tariff", but if I click on it, nothing happens. I tried to reset my network settings - my iPhone rebooted, but the problem persisted. What could be the reason?

[Re-Titled by Moderator]