The statement you provided isn't inherently rude, but it can come across as a bit blunt or matter-of-fact. To make it sound more polite or friendly, you might consider rephrasing it. Here are a couple of options:
1. "H entered the check-in mileage and is now looking for guidance on how to enter the check-out mileage."
2. "H has successfully entered the check-in mileage and would appreciate some help with the check-out process."
By adding