Let me provide some information about your concern, SP-1.

You can upload CSV file to QuickBooks Online like your bills, invoice and bank data. And then, match it later to your downloaded bank transactions. Let me guide you how:

1. Click on the Settings icon.
2. Click on Import Data.
3. Select what you want to import like bills or invoices.
4. Click on Browse to upload the CSV file.
5. Click Next and map the fields to match in QBO.
6. Follow the prompts to complete the import.

Once done, the bills will show in your Expenses tab section and then can match to the downloaded bank transactions. 

Check this link to learn more about: Common questions about importing data in QuickBooks Online.

Drop by again in the Community if you have other questions importing your data.