In this app we can't use getch command and conio.h header file ????

Answer 1

just because of different complilers

Answer 2

There are alternatives provided by C++03 that the SoloLearn C++ compiler complies to.

Answer 3

All program inputs go through the code Environment's proprietary input screen rather than a console for inputs. Thus, the <conio.h> header file will not work.
As for getch(), you will need to define it in your code because getch() is only defined in the <conio.h> header file. The only header file that compiles is the usual <iostream> for all the standard functions (cout, cin, etc.). All other header files need to be manually inserted in the main.