abp/templates/app-nolayers/aspnet-core/MyCompanyName.MyProjectName.Host.Mongo/Services/MyProjectNameAppService.cs

using MyCompanyName.MyProjectName.Localization;
using Volo.Abp.Application.Services;

namespace MyCompanyName.MyProjectName.Services;

/* Inherit your application services from this class. */
public abstract class MyProjectNameAppService : ApplicationService
{
    protected MyProjectNameAppService()
    {
        LocalizationResource = typeof(MyProjectNameResource);
    }
}