I appreciate you reaching out to us in the Community, @edofrancisco733.
Thanks for providing the details of your concern. I'm here to share some information about adjusting inventory quantity and asset value in QuickBooks Online (QBO).
If you've already changed or adjusted the inventory quantity, you need to create journal entries using the Inventory Asset account to change the asset value.
To set up an asset account yet, here's how:
1. Go the Gear icon at the top and pick Chart of Accounts under Your Company column.
2. Click New on the upper right, then select either Fixed Asset or Other Asset on the Account Type.
3. Pick the detail type of asset (select the closest possible), then Next.
4. Enter a name, then depending on the item, mark the Track depreciation box. (If selected, the system will automatically create a Depreciation subaccount for the item).
5. Enter the original cost fields, then Save & close.
Once done, you can now create a journal entry to change or adjust the asset value. I highly suggest consulting with your accountant for further guidance.
For additional information, you can also check out these articles for future reference:
That should get you pointed in the right track. Please reach out in the comments to let me know how it goes. I'm always here if you need anything else. Have a wonderful rest of the day.