First, some semantics… The xEM and xNT implants are both “RFID”. RFID encompasses a plethora of short range communications with passive tags. So the lock is low frequency (LF) RFID. Your xNT is Hight Frequency (HF) RFID.
I have this lock. Read range is pretty typical for glass tags, meaning it’s terrible compared to cards or fobs. The issue is that it is designed to be installed inside the cabinet on the door and the tag is read through the door. This lock will not read glass tags through a 3/4" door. It would need to be much thinner than that,
Anyway to answer your actual question… Preferrably, you’d get a Proxmark with the custom LF antenna DT sells. https://dangerousthings.com/product/proxlf/ then you will be able to do anything you need to with HF and LF tags.
A more dangerous alternative is a “blue” cloner. Not all blue cloners are the same, and all of them have the potential to brick your xEM if you aren’t super careful.
If you go down this risky road you’ll want to read this
Then this
And you’ll want to get a “three beep” version of the cloner.
https://www.amazon.com/Portable-Handheld-Writer-Copier-Duplicator/dp/B07QMY67YR/ref=sxbs_sxwds-stvp?
Don’t say I didn’t warn you.