Can't connect to SQLSExpress from application after publishing to IIS. What is not configured?

Question

ASP.NET

Good day!
I have an application on ASP.NET Core 2.1. As suggested VS was running under localdb. But then I decided to make a publication on ISS on Windows 10. As I read on the forums, localdb is no longer suitable for this, so I installed SQL Server Express accordingly. Enabled IIS:

Installed .NET Core Windows Server Hosting.
Working under VS changed the db connection from

"AllowedHosts": "*",
  "ConnectionStrings": {
    "InstituteContext": "Server=(localdb)\\mssqllocaldb;Database=Institute;Trusted_Connection=True;MultipleActiveResultSets=true"

Accordingly to:

"AllowedHosts": "*",
  "ConnectionStrings": {
"InstituteContext":"Server=MATKOVSKIY\\SQLEXPRESS;Database=master;Trusted_Connection=True;"

Working on VS everything works fine, I add new records to the database.
Further I do the publication type Folder.
I create a new site on IIS:

I go into the browser and type localhost/ => the home page is loaded, but as soon as I go to the people page where I need to show a selection from the database =>
Maybe someone came across? I understand that I did not configure something in SQLServer Express?
Thanks in advance!