How i can see installed CUSA

Not really. This has been asked before already and there has been no real answer.

There are dumping and packaging tools however that you can use to open FPKG/PKGs and it will tell you the CUSA, version and etc.

Example: https://www.psxhax.com/threads/ps4pkgviewer-a-ps4-pkg-viewer-by-lman-theleecherman.4784/

Or: http://www.mediafire.com/file/81vlsovsn3btv7j/Fake_PKG_Tools_v1.5.1.rar (contains a lot of other tools but there is also a FPKG/PKG viewer tool in there)