Welcome to the Community, @TBBCyberjaya.

Currently, the QuickBooks mobile app does not have the ability to track stock or inventory by-products. However, you can manage your stocks through the web browser as a workaround. This allows you to receive alerts when it's time to restock and provides insights on your purchases and sales. Additionally, you can enter non-inventory products and services to quickly add them to your sales forms.

Here are the steps to set up your inventory using the QuickBooks browser:

Step 1: Turn on inventory tracking

1. At the gear icon, select Account and Settings.
2. Click on the Sales tab.
3. Choose Edit✎​ in the Products and Services section.
4. Turn on the Show Product/Service column on sales forms.
5. Turn on both Track quantity and price/rate and Track inventory quantity on hand.
6. Select Save and then Done.

Step 2: Add your inventory products

You can now add your inventory items and other products and services you sell into QuickBooks. You can add products you want to track as part of your inventory. These are products you sell that allow you to set and track product quantities. Add products and services you buy or sell, but don't track as part of your inventory.

Step 3: Keep track of what you sell

Once you've set up all your inventory products, you can track them when they sell. There are two ways to do this:

Create an invoice if you’ll get paid later.

Add a sales receipt if your customer paid on the spot.

QuickBooks then decreases what’s on hand by the amount on the invoice or sales receipt.

Step 4: Restock your inventory

You can place orders directly in QuickBooks, track incoming inventory, and update on-hand quantities automatically.

Step 5: Use reports to check the status of your inventory

Access reports to instantly see your best sellers, what’s on hand, the cost of goods, and more.

For a more detailed process on this, you check this article: Set up and track your inventory in QuickBooks Online

I'll also add these articles to guide you through the process of managing your stocks in QuickBooks: 

• Change product and service item types in QuickBooks Online
• Add inventory products in QuickBooks Online
• Inventory management

I'm only a comment away if you have any questions about managing your stocks or inventory in QuickBooks Online. Take care and enjoy your weekend!