If you have Hike set to send data only to QuickBooks, any adjustments you make manually in QuickBooks will not flow back into Hike.
You may want to enable the two-way option if you want data sent to and from Hike and QuickBooks. Refer to the Sync Settings section of the article named How to Integrate QuickBooks Online Plus - first time setup, Sync Settings on the Hike Support Portal.
To adjust the quantity of your inventory items in QuickBooks:
Go to + Create, then select Inventory qty adjustment.
Enter the Adjustment date.
In the Inventory adjustment account dropdown, select the appropriate account.
For each item, enter either a new quantity or a change in quantity.
In the Memo field, enter details about the adjustment.