Thanks for reaching out!
We have added a GDPR section inside Judge.me to help you deal with your Data Subject Rights: https://judge.me/shop/gdpr
We have considered adding such check boxes, yet upon reviewing how we process this personal data of your customers, we think that the context and action of the customer is sufficient for allowing this processing of data. Please note that this user is not added to your newsletter or receives any communication other than about this single review. Leaving personal data for a review will only serve for this one purpose.
Here is Recital 32 from the GDPR that is usually referenced: http://www.privacy-regulation.eu/en/recital-32-GDPR.htm
We would be glad if you can state your use case in this feature request though: https://judgeme.featureupvote.com/suggestions/11120/gdpr-compliance-checkbox-while-leaving-a-review
This will help us to understand your concern better and we can consider adding such a checkbox in the future 🙂