strcpy()함수가 destination인자로 포인터를 받아오면 안되는 것같은데 맞나요????

#include <stdio.h>
#include <string.h>
 
int main ()
{
  char str1[]="Sample string";
  char str2[40];
  char* str3; //!!!!!!!!!!!!!!!!!
  strcpy (str2,str1);
  strcpy (str3,"copy successful");
  printf ("str1: %s\nstr2: %s\nstr3: %s\n",str1,str2,str3);
  return 0;
}