Just change the notifications that I leave in the examples for the ones you decide before building and enjoy.
#include "ps4.h"
int _main(void) {
// Init and resolve libraries
initKernel();
initLibc();
jailbreak();
// Pop-up notifications to show
printf_notification("PS4 Show Notify by GamerHack");
sceKernelSleep(1);
printf_notification("This is an Example");
sceKernelSleep(1);
printf_notification("This is another Example");
sceKernelSleep(1);
printf_notification("This is all, Bye!");
return 0;
}