Embedded apps currently rely on 3rd party cookies to authenticate. When the app loads, it sets a cookie in the browser. 

The app keeps track of the cookie and any other relevant information in a session on its server. The browser sends the cookie to the server with every request. For privacy reasons, browsers are now restricting the use of 3rd party cookies. This means that you can't use cookies to keep track of sessions of embedded apps. As an alternative to cookies, use session tokens to authenticate your embedded app. 

You can find more detail about it from Shopify Official Documentation

Currently, we working on it, but it not ready yet. We will inform you when it done. In this case, we recommend you following this guide to use the app without error

Safari Browser

Please turn of  Prevent cross-site tracking in Safari on Mac follow:
  1. In the Safari app on your Mac, choose Safari > Preferences, then click Privacy.
  2. Uncheck “Prevent cross-site tracking.” Unless you visit and interact with the third-party content provider as a first-party website, their cookies and website data are deleted.

Chrome Browser

Allow cookies on the app websites

1. Click the "Customize and Control" button

2. Select the "Settings" menu item

3. Search for the Cookies settings

4. Scroll down to "Site settings" and click it

5. Click the "Cookies" item

6. Allow cookies on app domain

Click add then insert domain name: social.arenacommerce.com