No problem at all — that can happen sometimes! You can think of the green sticker as a "training" line to help you get started with your bin. If it falls off, feel free to dispose of the sticker in the trash. You should still be able to see a matte, light gray interior ring where the fill line is, so you can use that as an indicator going forward. Or, check whether or not you can see the paddles. If you can’t, it’s time to empty!
We'll also do our best to detect when your bin is getting full based on the weight in the bucket, and let you know with a pulsing green light on your lid and a notification in your Mill app. Just note that some Food Grounds are more dense than others, so that fill line on your bucket is really your best indicator of when it's time to empty.