Recursion is often unintuitive for beginners, to understand this code we should simply it a bit

int main(void)
{
    int height = get_int("Height: ");

    draw(height);
}

void draw(int n)
{
    if (n <= 0)
    {
        return;
    }

    draw(n - 1);
    printf("%d",  n);
    
    printf("\n");
}

Inputting 3 should now give us a output like

1
2
3 

Try to understand that case first and than muddle it up with the loop.

If you examine it in a debugger look at the Stack trace. If you use gdb its bt in a visual debugger it's probably the list of function names next to the variables