The name of the Gutenberg block is Submit Review. It can be found in its own category/section called Ultimate Reviews. Alternatively, when you add a new block, you can just search for review or Submit Review and add that block to the page.
You will see two options in the right sidebar:
- Product Name: Specify the name of the product you want the review submission to be for. If left blank, it will allow the user to specify/choose which product they are leaving the review.
- Redirect Page: Specify the URL of the page you would like the user to be redirected to after they submit the form.