Is it an xNT or a NExT? I only ask because the NExT has its config bytes protected by default. If it’s an xNT then download the “Dangerous NFC (BETA)” app and apply a password to your xNT.
You don’t have to be super worried about fucking up your implant. The only reason you need to protect the config bytes is if you were trying something weird or untested. Normal reading and writing isn’t an issue.
After you’ve done that, here is a short guide to writing a record to your implant with Tagwriter app.