Inside the function parameter list, char arr[] is absolutely equivalent to char *arr, so the pair of definitions and the pair of declarations are equivalent.
void function(char arr[]) { ... }
void function(char *arr) { ... }
void function(char arr[]);
void function(char *arr);
The issue is the calling context. You provided a string literal to the function; string literals may not be modified; your function attempted to modify the string literal it was given; your program invoked undefined behaviour and crashed. All completely kosher.
Treat string literals as if they were static const char literal[] = "string literal"; and do not attempt to modify them.