Can I run a transaction report for just one customer with customized dates 12/15/2019 to present

Yes, you're able to run a transaction report for just one customer and show how much they've paid in detail with QuickBooks Online (QBO), @aaastorageofpres. I can guide you how.

You can filter specific customers and focus on the details that matter the most to you through the customization feature in QBO. Let's go to the Reports menu and pull up the Transaction List by Customer report. Then, make sure to set the appropriate date range to get the accurate data. Here's how:

1. Go to the Reports menu.
2. Type in Transaction in the search field and select Transaction List by Customer.
3. Click the Customize button.
4. In the Report period field, select the Custom option. Then, manually input the From and To dates (i.e.,12/15/2019 to 01/22/2021).
5. Go to the Filter section and select the name of your customer in the Customer drop-down field.
6. In the Transaction Type field, select Payment.
7. Click Run report.

I've attached a screenshot below that shows the last four steps.

You can learn more about customizing financial and transaction reports through this article: Customize reports in QuickBooks Online. It also includes details about sharing custom reports via email.

Additionally, you're able to save your report's customization settings. This way, there isn't a need for you to customize the report whenever you need one. You can refer to this article for the step-by-step guide: Memorize reports in QuickBooks Online. 

I'm just around if you have other concerns about pulling up and customizing reports in QuickBooks. Take care always.