You've got the right place to help you with your QuickBooks questions. I can share some information about setting up the Sales Tax feature in QuickBooks Online.
Before anything else, may I know what error message are you getting when setting up sales tax? Knowing more about this will help me provide the most accurate resolution for you.
However, if you're getting a blank screen after the setup, our engineers identified this as an ongoing issue in QuickBooks Online. They are diligently working to roll out a fix for this unexpected behavior. While we don't have the exact time-frame on when the problem gets resolved, I'd recommend contacting our Support Team. There they can view your account and add you to our list of affected users.
Once added, you'll get live email notifications when an update is available. Here's how to contact us:
Click the (?) Help menu at the top right section of your QBO Dashboard.
Tap the Contact us button.
You can have our live support agents add you to the investigation number INV-24183. That should point you in the right direction, @aliciamoyer76.
I've also added here some related articles to help you set up the service: