In RepU, open your widget, choose light or dark and left or right, then click Copy next to the embed snippet.
In your TypoScript setup, add a page.footerData entry as a TEXT object that holds your code. For example, page.footerData.1000 = TEXT, then set its value to your code.
Need more detail? See the official TYPO3 guide.
Save your TypoScript and clear all caches, then open your live site to see your Google reviews.
Check your live site in a private window, not the editor or preview. A domain-locked widget only shows on your own domain.
Clear all caches after saving. Check your TypoScript is in the root template your pages use.