Can a teen get implants safely?

This ring has a changeable 4 Byte NUID

Correct, and if you want to store a URL, then this is the one you want.

BOTH rings have an LF T5577.

Regarding your iPhone “issue”

Apple don’t think the people who lease own their iPhone handsets can be trusted to manage the security risks of allowing access to your contacts, so you can’t share a VCard.

Luckily for you there is a workaround.

Check out these as see if one suits you