Hi @PerserPolis-1732 ,
the installled software on each Computer is gathered throough the SCCM Software Inventory and is imported than in SCSM by the SCCM connector. So, what yyou need to do, is to integrate your SCCM with SCSM in order to populate the data. In order to do that you can follow this guide:
Import data from Configuration Manager into Service Manager
https://learn.microsoft.com/en-us/system-center/scsm/import-data-cm?view=sc-sm-2019
The same would apply to the "All Software" view...As soon as you have synced the Installed Software on your Computers, the view will also get populated with All Software Items.
I hope I was able to help.
----------
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Stoyan Chalakov