Review snippets structured data issue

From Topic Ratings Plugin - #399 by Chandra - plugin - Discourse Meta

I also wanted to draw your attention to this one below, based on a google search console notice I received. Aligning ratings to google markup will be a game changer for google rankings, so please consider it.

Google Notice:

Search Console has identified that your site is affected by 1 Review snippets structured data issue(s). The following issues were found on your site. We recommend that you fix these issues when possible to enable the best experience and coverage in Google Search.

Top critical issues*

Rating is missing required best and/or worst values

*Critical issues prevent your page or feature from appearing in search results.