Welcome aboard to the Community. I'm here to assist you with any concern you may have about Bills in QuickBooks Online.
Right now, you can only print the bills through the Transaction list or by running reports available in the QuickBooks system. For now, an option to print directly on a single bill is not yet available in the Online version.
To print bills through the Transaction List section, please follow these steps:
You can check this screenshot:
If you want to print them through a report, you can try running the Transaction List by Vendor report.
Feel free to reach out to me for any additional assistance you need concerning the printing of bills. The Community is always here to help.