I need help fixing a nonce and permissions error when trying to connect to an external app -- 2

I have a wordpress website for a brewery that has an app to find where the beer is sold in stores. When you click the "find it near you" button, a map is supposed to pop up that shows all of the locations that beer is available at. However, we are getting errors which you can see by trying it yourself - [login to view URL] 1.) It worked on the development site, but when we launched the site with our new URL and new hosting on WpEngine it no longer works. The development site has been deleted so I don't have access to it for a live example. 2.) The app repository was created on GitHub (I don't have access to that), and is hosted on Heroku (I do have access to that). When checking Heroku logs, there is a nonce error. The original developers are saying if the nonce error and permissions were fixed then it would work, but I don't know how true that is.