I appreciate you for posting about this concern, bscoldstorage. Let me provide information on why the customer transaction report is not showing in the QuickBooks Mobile app.
In the QuickBooks Mobile app, you can only access the Profit and Loss report and the Balance sheet. Thus, you won't be able to locate transaction reports such as invoices and estimates.
To access this information, please log in to your mobile web browser. From there, you can access the Transactions List by customer and other reports. Once you're in, you can select the specific transaction or customer. If you need to customize, you can filter the date range and transaction type to invoice and estimate.
Additionally, if you need help in recording the payments from your customers using a mobile app, you can refer to this article: Receive an invoice payment using the QuickBooks Online mobile app.
I'll be around if you need further assistance in managing reports in QB Mobile app or with any related tasks. I hope you have a pleasant day ahead. Keep safe always!