Please when I keyed an opening balance for an inventory and I save there is a pop up that says '' Select a non-inventory account for your deposit''. So unable to save

Let's check why you're getting the pop-up when entering an opening balance for an inventory, trenor.

Are you getting this message when creating an inventory account on the Chart of Accounts? If so, you don't need to put an opening balance on the account. 

To save the inventory account, cancel it, and create a new one. Then, save it without entering a balance. See the attached screenshot for your visual guide.

When you buy an inventory item, your bill, check or credit card charge will debit the item's Inventory Asset account. Then, credit the Accounts Payable, bank, or credit card account.

I'm adding this article to help manage your inventories: Set up and track your inventory in QuickBooks Online. It'll tell you how the system handles your inventory accounting.

If your situation is different, please let me know by commenting below. I'll be right here to provide the steps so you can save the inventory account.

 I'll keep this post while waiting for your response.