You can use your own icon (a PNG or JPEG image file) for your Extra on the cleaning booking form:
Go to Settings -> Extras Click the Delete button next to the Extra you want to delete When the dialog asks “Are you sure?”, click OK.
Go to Settings -> Extras Click Add New Enter values for Name and Price. Click Save.
Go to Settings -> Extras Drag and drop an Extra to a new position in the list Your Extras will be displayed in your Booking Form identically to how they appear in this list.