Tilt and Raspberry Pi Zero W

Need help please I think I am out of my depth
I am trying make a repeater so that my tilt will read through a stainless steel fermenter and refrigerator, I have downloaded this at GitHub https://gist.github.com/N3MIS15/72658a024eb0dfde6d1c0958092acd42
on an ESP32 powered by a little book converter and use a small power pak. It appeared to download 100%. Light is on on the book converter and the ESP32 .I think this is using Bluetooth.
Q1 Is there something I am missing ?
Q2 Can I extend the Bluetooth range of the PI Zero W which would make it easier
This fellow seemed to get it working :- https://www.youtube.com/watch?v=D_EpFoi8zaE
Any help is much appreciated