A button and slider at same digital pin on Adafruit ESP8266

[Gunner]

And use the search function in this web page… i.e “button slider led” shows a few threads, including this one…

2 way lighting circuit control with blynk and feedback updates

You could try something like a current flow detection device, or this one. No need for the value of the current, just whether it is on or off should be sufficient. Then using that logical on/off determination show the activity in the app with the Blynk.virtualWrite() as @Dmitriy mentioned. I have done something similar (without the active hardware detection) using an app slider and a single physical button/switch combo to control the brightness of an LED #define WLED 6 // Set Physical LED p…

It is not exactly what you are looking for, examples rarely are… so study it and tweak it to your needs.