When a cleaner is done with a cleaning, the email template sent to customers should simply ask the customer to select a happy smiley face, neutral, or sad.
Or you can have a color coded options of selecting 1 thru 5 in the email. With 1 being red and 5 being green.
Then when on either of those are selected, it will automatically prompt the customer to add feedback if needed and if they dont add feedback, it will simply add the rating in BookingKoala either way.
Sending customers to the dashboard, prompting them to login to their account and leaving a review is a multistep process that customers rather ignore.
Having a simple solution by selecting a rating of a smiley face and having that apply automatically w/the option to leave feedback is much simpler way to gather customer feedback.