In case, you want to ship more than one quantity of a similar Shopify SKU, please follow the below-mentioned steps.
Open your Shopify store. Go to the Apps section, further click on the Auto Multi-Channel Fulfillment app.
Once you are inside the app. Go to the Products Linking page of the app. Now, using the Shopify SKU search field, enter the SKU that you want to ship in more than one quantity. Once, you have your search result, click on the Update button corresponding to the desired SKU. Below is a screenshot to help you understand this visually.
Once you have clicked on the Update button, you will be seeing the below-displayed pop-up. Now, for example, if you are interested in shipping 10 quantities of your desired Shopify SKU, enter 10 in the Quantity box. Once entered, just click on the Submit button.
Once configured, this is how it looks like.
Congratulations, you have successfully mapped your desired Shopify SKU with its desired quantity.