You can update the stock from the inventory module using the steps mentioned below:

Step 1:

In every product list, there is a pen icon below ‘Total Stock’. Click on the pen icon to edit the stock.

Step 2:

You will now be redirected to a stock update screen where you can edit the total stock of the product, buffer stock and threshold value. 

Step 3:

The stock will be updated once you click on the update stock button.