Why am I getting same random numbers from a user created new_random() function that uses rand() and srand() in C++? [duplicate]

I have a problem with the following code that I have written in C++. I need this kind of function in some other program. The problem is I am getting the same random numbers when I call the function multiple times. I don't know why this is happening and is there any way to get it fixed.

#include <cstdlib>
#include <ctime>
#include <iostream>
#include <random>

using namespace std;

int new_random()
{
    srand((unsigned)time(NULL));
    int r{rand()};
    return r;
}

int main()
{
    int a{new_random()};
    int b{new_random()};

    cout << a << endl
         << b << endl;
}

In every run, I am getting a and b to be same.

I will highly appreciate if somebody can show me some light to get two different random numbers in this way. Thanks a lot.