@michele-trotta
Hi everyone ,
sorry for the delay, but the problem has been solved.
When the citrix workspace web app is launched it is asked to open a new page with microsodt EDGE. When "Open APP" is confirmed, a file with the ICA extension is downloaded. In this file there is a parameter that identifies an internal proxy that citrix will use. Now once this value has been discovered, it must be included in our Squid and the game is done!!!!
Good job everyone
Michele