This is the source code of the Sonos-Remote-Station: https://twitter.com/tmjns92/status/1256179074495627264
This project was built with the PlatformIO IDE. So, I recommend you to install the PlatformIO extension for Visual Studio Code before you start. Don't forget to edit these lines before uploading:
#define SSID "________" // Your SSID
#define PASSWORD "________" // Your Password
IPAddress g_MasterBedroomIP(192, 168, 8, 112); //Your Sonos Speaker IP
const char g_MasterBedroomID[] = "1CBBFW9E899ED"; //Your Sonos Speaker ID