"Out of the box" Stackla Event Screens do not run through a proxy and all social content is stored on the original social network. As such in order to work, you will need to whitelist both Stackla's Event Screen domain, plus each of the source networks you will be displaying content from.
If your business requires your Event Screen to come through a proxy (i.e. you are not comfortable whitelisting social sites), please contact your Customer Success Manager for scoping and quotes.
For any further questions or queries, please send an email to support@stackla.com or submit a request and our support team will get back to you.