What this error mean : expression must have pointer-to-object type but it has type struct add stock in C

#include <stdio.h>
int i, n;
struct add_stock
{
    char fullname[30];
    int stocks;
    char com_name[30];
    int shares;
    float price;
    float total;
    int totalmoney;

} add;
int main()
{

    printf("Enter full name : ");
    scanf(" %[^\n]s", add.fullname);
    printf("Enter the no. of stocks you want to purchased : ");
    scanf("%d", &n);
    for (i = 0; i < n; i++)
    {

        printf("Enter the name of the company : ");
        scanf(" %[^\n]s", add[i].com_name);

        printf("Enter the no. of shares you want to purchased : ");
        scanf("%d", &add[i].shares);

        printf("Enter the price of each share  : ");
        scanf("%f", &add[i].price);

        add.total = add.shares * add.price;

        printf("Toatl money invested in this stock : ");
        scanf("%f", &add[i].total);
    }
    printf("Total money invested : ");
    scanf("%d", add.totalmoney);

    return 0;
}