Please describe step you have done to publish.

Publish and deploy SimplCommerce is just like publish and deploy standard ASP.NET Core applications.

Please checkout the docs from Microsoft https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/?view=aspnetcore-3.1

It does work on IIS on Server 2016

Had to work the web.config file

after publish I get error cannot open SimpleCommerce. Login failed for AppPool\DefaultAppPool.

What do you have for .NET CLR version: ?
Also, what do you have for Managed Pipeline: ?

Are you able to offer any more details?
Have you modified the web.config file?

Did you install the .NET Core Runtime Environment Hosting Bundle?

Hosting bundle is installed installed
DotNet core 3.1.301
I am using the default web.config file that is being generated on publish.
APPPOOL is using no managed code

Also if I manually create the database then it gives error Unhandled exception. Microsoft.Data.SqlClient.SqlException (0x80131904): Invalid object name 'Core_AppSetting'.

If I understand the error code, is your SQL Server on another Server separate from your IIS Server?
You may need to run Netstat when its trying to connect, so you can see which port its trying to establish a connection with the SQL Server.

In your file " appsettings.json " is it pointing to your SQL Server? If so, are you using User & PW?

You still may need to update the Handlers for ISAPI, Remove WebDavModule, in your web.config file.
My Web.Config file is still being worked out, and still running some Pen-Test.

@altumcon follow these steps https://github.com/simplcommerce/SimplCommerce#steps-to-run