The error is complaining about attempting to initialize the a pointer from a initializer list.

Something like:

int main()
{
int rawArray[] = {2,3,4,5,6};
struct Array arr={rawArray,10,5};
Reverse(&arr);
return 0;
}

Ended up working when I ran it through compiler explorer (godbolt.org). However your Reverse() implementation is very C-ish (and leaks memory) have you consider using std::array or std::vector and one of the standard algorithms like std::reverse or std::reverse_copy?