You can display the rating of your product using the Star review option but to use this option you must be installed any of the review apps listed in the option.
Below is the app name which we have integrated with iCart app:
01) Judge.me
02) Loox
03) Rivyo
04) Stamped.io
05) Ali reviews
06) Reviews.io
07) Product reviews
08) Yotpo
09) LAI Product Reviews
See how the result is showing