How can I block the constant popups asking me to upgrade?

Hello there, julian16.

Let me share information about blocking pop-ups in QuickBooks Online (QBO).

The pop-up notifications are designed to suggest and guide you on how to improve your QuickBooks experience. I understand that the ads may affect your navigation. However, turning off or blocking permanently the suggestion pop-ups is unavailable. In the meantime, I recommend clicking the X or No, thanks buttons to remove the pop-ups.

I know how the feature you want would be helpful in the program. The Community recognizes feedback and suggestions from customers like you that can help us improve our product and services to our customers' delight. I suggest sending feedback while this feature is not an option.

To send feedback, follow the below steps:

1. Go to the Gear icon at the top.
2. Select Feedback.
3. Enter your comments or product suggestions. 
4. Then select Next to submit feedback.

I've also included this link to help you effectively manage your account for future reference: Learn about QuickBooks Online with how-to videos.

Please don't hesitate to leave a comment below if you have other concerns. I'm here to help. Keep safe always, julian16.