You can give feedback on the Rental Mobile Operations app.
The feedback is sent to the app provider: STAEDEAN.
Steps
On the home page of the app, tap the floating action button > STAEDEAN Feedback.
Note
On a Windows device or browser, on the taskbar, tap STAEDEAN Feedback.
On the dialog, select you rating.
Enter text to tell why you choose this rating.
Tap Submit.