stars not valid rating in google product review data highlighter

Can someone respond?

Where are you seeing that “the stars are not a valid rating tag”. The stars aren’t actually what serve the rating data, but rather the rating data is served numerically in meta tags. You can run google validation on your markup here https://developers.google.com/structured-data/testing-tool/. Can you possibly provide me with the url of the website at which you are having trouble?

Thanks,
Charlie Maxwell
[NM_Developer]

The validation works, but when I use the data highlighter, I get that error.
How/When does that rating show up in search results?
https://dulcecouturecakes.ca/
It’s on the home page and in testimonials

How do I test that the stars will show up in the results of a search on Google.

Thanks for your reply.