In file included from C:\Users\Michal\Downloads\opentherm-gateway-simple-main\otgw_simple\otgw_simple.ino:10:0:
C:\Users\Michal\Downloads\opentherm-gateway-simple-main\otgw_simple\src\ESPAsyncWebServer\ESPAsyncWebServer.h:26:10: fatal error: functional: No such file or directory
#include <functional>
^~~~~~~~~~~~
compilation terminated.
exit status 1
Hello, i tried to compile it for my ESP8266