For the longest time there’s been no native support for NFC tags in iOS, but from iOS version 14 and from iPhone 7 you can now read NFC tags, and iOS will act on the content, e.g. URLs. That way you can write a CliqTags URL to an NFC tag and have users read the NFC tag to see the site pointed to, similar to how QR codes and Eddystone beacons are used.
This article goes into more details about this: How To Read NFC Tags With An iPhone
Can I use NFC tags with CliqTags, and if so how? has been updated to reflect this.
All NFC tags we had access to worked fine.