[Arduino IDE demo source code for KC868-A32]--#07-KC868-A32_Web_server_code

[tugalsan]

Board Manager: Yes I checked it. esp32 is version 1.0.6.
Library Manager: I think header files are related with library manager. Now, for no reason, it started giving me below error

Code:

Compilation error: PCF8574.h: No such file or directory

I need to find which libraries should i install to use the above example.