Enable inventory tracking
When a product's inventory is tracked in Shopify, the inventory quantity that's available at a location is updated automatically when you receive a transfer that includes the product.
From your Shopify admin, go to Products.
Click the name of the product that you want to track.
If the product has variants, then click the variant that you want to track.
In the Inventory section, check Track quantity.
If you want to allow customers to purchase the item when it's out of stock, then check Continue selling when out of stock.
In the Quantity section, enter the quantity information for each location.
Click Save.
From the Shopify app, go to Products > All products.
Tap the product that you want to track.
If the product has variants, then tap the variant that you want to edit. You'll have to set inventory tracking for each variant individually.
Tap Inventory.
On the inventory screen, enable Track quantity.
If you want to allow customers to purchase the item when it's out of stock, then enable Allow purchase when out of stock.
Tap Quantity, and then enter the number of units that you have for the product or variant.
Tap Done.
Tap Save.
Tap the name of the product to return to its details screen.
From the Shopify app, go to Products > All products.
Tap the product that you want to track.
If the product has variants, then tap the variant that you want to edit. You'll have to set inventory tracking for each variant individually.
Tap Inventory.
On the Inventory screen, enable Track quantity.
If you want to allow customers to purchase the item when it's out of stock, then enable Allow purchase when out of stock.
In Quantity, enter the number of units that you have for the product or variant, then tap
✓.Tap
✓.Tap the back arrow to return to the product details screen.