Making WPSL work on two domains

Having issues getting the Store Locator to work on a domain I redirected. The actual domain is mydomain1.com but we’re bringing over people from a previously active domain and pointing any page that’s mydomain2.com/xxx to the Envy site.

So the store locator at https://mydomain1.com/find-a-provider/ can appear in the browser as https://mydomain2.com/find-a-provider/

But only on mydomain1.com does the map actually work. On using the other domain, I noticed in console issues such as:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://mydomain1.com/wp-admin/admin-ajax.php?action=store_search&lat=34.154459599999996&lng=-118.43917269999997&max_results=25&search_radius=50&skip_cache=1. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).

Now obviously, mydomain1 and mydomain2 are not the actual domain names, but I wanted to use these as examples.

Is there some way I can make this work for both domains? Or must I use mydomain1 exclusively on this page?

The page I need help with: [log in to see the link]