Usually when this happens, we've been able to log out and log back in once or twice and the button will be there. If that doesn't work, there are a few other ways to get the Review Link using the new interface.
After logging in using your GPB profile credentials, on the same tab, do an exact google name search for the business. Your browser should look like Image_1 (attached). Now, if you click on the "Google Reviews" link (Option 1), it will open a window showing your reviews with a "Get More Reviews" button (Image_2), click on that and you'll get the Reviews Link to share with customers. Going back to Image_1, you can also click on the arrow (Option 2) a couple of times and you'll see a box that says something similar to "Get your first reviews". If you click on that it will take you directly to the Reviews Link that you can share with customers.
If that doesn't work, it would be helpful to post some pictures of what you are seeing. Hope this helps!
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.