Glad to have you here in the Community, @AY6.

I can help you add fixed assets in QuickBooks Online (QBO).

We'll have to create first an asset account in QBO. This where we track the current value and depreciation of your assets.

Here's how:

1. Go to the Accounting menu, and then choose Chart of Accounts.
2. Click New at the upper right corner.
3. From the Account Type drop-down arrow, choose Fixed Asset or Other Assets.  
4. In the Detail Type drop-down arrow, select the option that nearly describes the asset. 
5. Enter the account name. 
6. Put a checkmark beside Track depreciation of this asset checkbox. 
7. Assign an Original Cost and enter the As Of date of the purchase.  
8. Click Save and Close.

Once done, record the Asset by using a Journal entry. I'll guide you how:

1. Go to the +New button.
2. Under Other, select Journal entry.
3. Set the Asset's purchase date as the Date of the entry. 
4. On the first line select the Asset account then record the item and enter the purchased value as a Debit. 
5. For the second line, use the same amount.
   • If the Asset's purchase needs to be recorded in your Bank Registers for historical reconciliations or any other reason, Credit the Bank Account.
   • If the Asset's purchase won't be listed in your books, Credit the Opening Balance Equity account, representing an Asset that was brought into the company on the book's starting date.
6. Click Save and close. 

For additional information on this, I recommend checking the following articles:  

• Create subaccounts in your chart of accounts in QuickBooks Online 
• Create a journal entry in QuickBooks Online 
• What to do if you didn't enter an opening balance in QuickBooks Online 

Also, here's a link for your reference on how to depreciate assets in QBO: Depreciate assets.

Keep me posted if you have other questions. I'm always here to help. Have a great day!