You can import products and servicesfrom text files or Excel spreadsheets into QuickBooks Online (QBO). For your reference, you might want to download a sample file here.
You'll want to ensure to map the information correctly and avoid any special characters for smooth importing process. See the approved characters list for more details.
To import:
From the Gear icon and select Import Data.
Select Products and Services.
On the Import products and services page, select Browse.
Then, follow the onscreen instructions to import products and services.