It looks like I am only able to access 2020 Quickbooks subscription payment history. How can I retrieve my 2019 Quickbooks payment history?

We can retrieve your payment history through the CAMPS page, hi21.

The bill payment that is posted on our QuickBooks account is for the latest year. We'll have to go to the Customer Account Management Portal Site (CAMPS) to view the billing for the previous years. I'll show you how:

1. Go to: camps.intuit.com.
2. Select QuickBooks Self-Employed.
3. Enter your credentials.
4. Go to Payment and Order Activity.
5. Filter the date range to 2019.
6. Click Go.

In case you want to update your billing and subscription details, you can check this article for the steps: Update your QuickBooks Self-Employed billing and subscription details.

I'm just around if you still need my help in updating your subscription details.