These can be very difficult to use. Step 1, remove the cover. Step 2, place the wire antenna across the length of the implant so the wire runs perpendicular across the implant, directly across the middle of the implant… like you’re cutting a worm in half.
Once positioned, tap the write button. Even if it does not work and does not beep, keep still until the write LED is off. Then re-position and tap the write button again. Moving during the write process could brick your xEM - https://forum.dangerousthings.com/t/quirks-of-the-t5577-cloning-tags-to-the-xem