It's nice to have you here on the Community forum. I'm here to share with you some information about the sales rep report.
Sales by Rep report is only available in the QuickBooks Desktop version (QBDT). I recognize your need for this feature. Thus, I'd recommend sending your product feedback. This way, our developers will know and can consider adding the said feature in future enhancements.
I can walk you through how:
Click the Gear icon at the top, and then choose Feedback.
Enter your comments or product suggestions, like "I'd like to customise my statements."
You can also attach a photo to emphasize your concern, and then select Next.