C - variables in header file not recognized - arrays

Question

I'm new to C and I'm trying to create an online grocery store where I can add items to the store and print the details of each product such as the name, number in stock, price, etc.
I'm having trouble adding a product to a product collection array and getting it to print. My biggest issue is that main.c seems to not recognize practically every variable declared in defs.h even though I used the include tag at the top of the file. I'm also not sure if my addProd() function makes sense and was hoping someone could verify?
main.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "defs.h"
int main(){
InventoryType store;
store.storeName = "Walmart";
ProductCollectionType p;
p.numProd = 0;
addProd(&p, 1001, "Grape juice", 12.5);
addProd(&p, 1002, "Pepsi", 4.3);
addProd(&p, 1003, "Apples", 34.0);
int choice;
printf("(1) Print inventory");
printf("(0) Exit");
printf(" ");
printf("Please enter your choice: ");
scanf("%d", choice);
if(choice == 1){
store->printInventory(p)
}
return 0;
}
void printInventory(ProductCollectionType* productArray){
int i;
for(int i = 0; i < numProd; ++i) {
printf("The BLANK store");
printf("-- Product #%d, %s, %d units, $ %.2f", productArray[i].id, productArray[i]->name, productArray[i].numUnits, productArray[i].price);
}
}
int addProd(ProductCollectionType* productArray, int givenId, char givenName, int givenUnits, float givenPrice){
for(i = 0; i < numProd; ++i){
productArray[i].id = givenId;
productArray[i].name = givenName;
productArray[i].numUnits = givenUnits;
productArray[i].price = givenPrice;
}
}
defs.h
#define MAX_NAME 40
#define MAX_PROD 20
#define MAX_UNITS 15
typedef struct{
int id;
char *name;
int numUnits;
float price;
}ProductType;
typedef struct {
ProductType* products[MAX_UNITS];
int numProd;
int nextId;
}ProductCollectionType;
typedef struct{
char *storeName;
ProductCollectionType* productArray[MAX_PROD];
}InventoryType;

Answer 1

Regarding the code:
void printInventory(ProductCollectionType* productArray){
int i;
for(int i = 0; i < numProd; ++i){
blah blah blah
There is no such thing as the "naked" numProd, numProd is a field of the ProductCollectionType type. Hence you would need something like:
for (int i = 0; i < productArray->numProd; ++i) {