Good to see you in the Community, finance-house-of.
I'm here to provide some information about your situation.
QuickBooks Online is not designed to keep track of inventory for multiple warehouses at the moment. What you can do is use the class tracking feature for your warehouse locations.
To enable the class tracking, here's how:
Go to the Gear > Account and settings.
On the left panel, select Advanced.
In the Categories section, enable the Track classes option.
Hit Save and then Done.
After turning on the feature, set up the classes by going back to the Gear > All lists > Classes. Then, assign the class when you add your inventory item.
I've got these articles that you can read for more information: