Xiaodash prevents you from flashing firmware via other apps or via ST-Link. This tutorial shows you how to do it nonetheless.
We need an ST-Link - you likely ST-Linked your controller before installing XiaoDash.
- Open XiaoDash. Connect to your Scooter. In General Tab, go to Debug and click on "Enter Bootloader Mode".
- Go to https://flash.bastelpichi.de and hook up the ST-Link. You should be familiar from there.
Go to XiaoDash, connect to your Scooter. Open the Basic Tab, click on Return to Stock. After that, you can flash SHFW via Bluetooth.