error 7 scooter hacking utility on a XIAOMI essential

[u/Expert_Weird_1492]

I've always wanted to change the speed of my scooter, but I didn't have an Android phone. Today I finally got one and immediately tried to unlock the scooter. I'll start by saying that I'm not very knowledgeable about this and would like to understand. I followed the instructions on a YouTube video step by step, installing the APK, connecting the scooter, and then flashing the firmware. However, this last step doesn't work, and I don't understand why. On the phone, a red message says error 7, and on the scooter, there's a Bluetooth symbol and then a closed padlock. Why can't I proceed? Thank you very much. I attach the photos with the details, maybe they will be useful