How to use IPCSochet

I have to Xojo apps , Test 1 and Test. 2
Test 1 has 3 buttons, Connect, Listen and Send
Test 2 has 2 Buttons, Connect, Listen and a Rectangle1

I want to change the fill color of Rectangle1 in Test2 from Test1 Send button

What code is needed

The example project will get you the basics of using IPCSocket:
Example Projects/Communication/IPCSocket.xojo_binary_project