You've reached the installer page of the Squeezelite-ESP32 project, where you can initialize new devices.
Plug the device to your computer using a usb cable or, as needed, a USB to serial adapter, select the hardware platform that matches your device, the version you wish to use and click on the connect button. Note that the I2S-4MFlash platform is the generic version that will work for most devices.
By default, the connect button allows setting up wifi credentials for devices already flashed with support for improv-wifi-serial
It is highly recommended to use the 16 bits versions. See the readme for more details
From the creators: "The first Open software Bluetooth speaker and much more".