Login Failed For User IIS APPPOOLSiteName | NT AUTHORITYLOCAL SERVICES | NT AUTHORITY SYSTEM
When I host my DOTNET core web application with Sql Server on local IIS then that types of error occurs . So you can run it in Administrator account in application pool.
How to Host your DOTNET Core Application on Local IIS
https://youtu.be/Q_A_t7KS5Ss