Server Error in Application - The resource cannot be found.

I have a Website that runs exactly as it should in localhost. When I upload it and want to run it on my domain, I get the above error with the following description:

Description:HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable.  Please review the following URL and make sure that it is spelled correctly.

My provider blatantly told me, that they don't give support for something like that, because it has to be due to my app being faulty.

my web.config is as follows:

<configuration>
   <location path="." inheritInChildApplications="false">
   <system.webServer>
     <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
     </handlers>
   <aspNetCore processPath=".\Homepage Core.exe" arguments="" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="outofprocess">>
     <environmentVariables>
        <environmentVariable name="ASPNETCORE_HTTPS_PORT" value="443" />
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Release" />
     </environmentVariables>
  </aspNetCore>
</system.webServer>
 </location>
</configuration>

Any ideas, what could cause this?