The problem with using other is that it is too general and not specific. Suppose I said:
Look at the other side of the receipt
Which side am I referring to? If you happened to be looking at the front, that would mean the back; if you are looking at the back, that comment would refer to the front.
Now, in your context, the word other would work, because the message is printed on one side of the receipt. But I still think it sounds a little clumsy. It's not rude, and it's not incorrect, but I think that this sounds much more polished and professional:
Look at the back of the receipt
There's one other advantage, too: you can use that same wording on a sign near the exit of your business, where the expression other side would not work as well:
Kindly look at the back of your receipt to find a link through which you can rate our service.
As a footnote, notice how I removed the comma after kindly. We're not supposed to proofread here, but that comma really shouldn't be there.