Hey there KD63,

It's always a pleasure to see new faces in the Community, Welcome! Thanks for reaching out to us here. QuickBooks Online is a great program that can help make running your business smoother.

At this time, the Biggest Donors report isn't a report that is available in QuickBooks Online. However, I encourage you to take a look at the Sales by customer detail/summary reports. You will have the option to filter the report. If you require further assistance, I recommend reaching out to the support team outside of the Community. They'll be able to verify your account details, as well as view your screen to better assist you. You can reach out to them by following one of these methods:

Schedule a Callback or start a Chat: click (?)Help in the upper right > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback or Start a Chat.
Social Media: Facebook and Twitter

If you have any other questions, feel free to reach out here.