Hi there, @finance16.
Uploading journal entries using a spreadsheet is currently unavailable in QuickBooks Online (QBO). However, you can consider creating them manually as you usually do or look for a third-party application that can import journal entries.
To find for a third-party app, click on the Apps tab at the left panel, then enter a keyword, like "Import Journal Entries." Or you can also visit our site to look for a third-party app: https://apps.intuit.com/app/apps/home.
You might also want to check out these articles to know more about importing data in QuickBooks:
Don't hesitate to leave a comment below if you have further concerns about importing. I'll keep an eye on your response.