SOMETHING IN MY FIRE WALL

Only you can decide that. Macs don’t really need an app for that, they can Airplay on their own.

If you downloaded and installed the App for some reason, then only you know what that reason was, and if you still need it and as such, should allow it.

Also, Please stop writing in all capital letters, its hard to read, annoying, and considered “shouting” in only forum etiquette.

Can you elaborate your issue

https://www.electronic.us/products/just-stream/

JustStream is a 2-in-1 application for streaming local files from your Mac and mirroring Mac display to any device that's compatible with Apple TV

Its an App you had to have downloaded and installed on a computer. Its in the firewall if it was used to attempt to stream.

Uninstall the App if you don’t need it.