At this time, responding to reviews from the Reputation Management dashboard is only supported for the following review sites:
Google Business Profile (provided the Google Business Profile account is connected and verified), and the review has not been removed or edited on the Google listing. If the original review cannot be found, it will return an error of "No External ID".
Facebook (account must be connected for the system to pull in review)
My Listing page
For other review sites, clicking on the 'Respond' button will redirect users to the live listing where they can respond to the customer's review.