ASP.NET Core WebApi Add-Migration Entity Framework Core

I'm trying to build a ASP.NET Core WebApi with Entity Framework Core and AutoMapper. When i try to use Add-Migration i get Exception has been thrown by the target of an invocation. at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)(I haven't made any changes to the Program class). I think the problem may be that the program cannot find the connection string.
This is my DataBaseContext Class:

    public class DataBaseContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            IConfigurationRoot configuration = new ConfigurationBuilder()
                .SetBasePath(AppDomain.CurrentDomain.BaseDirectory)
                .AddJsonFile("appsettings.json")
                .Build();
            optionsBuilder.UseSqlServer(configuration.GetConnectionString("DataBaseContext"));
        }
        public DataBaseContext(DbContextOptions<DataBaseContext> options) : base(options)
        {
                
        }

        public DbSet<Director> Directors { get; set; }

        public DbSet<Movie> Movies { get; set; }
    }

This is appsettings.json:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "DataBaseContext": "Server=DESKTOP-LLPVCRN\\KISIELSQL;Database=KredekMovieManagement;Trusted_Connection=True;MultipleActiveResultSets=true"
  }
}

This is Startup.cs:

public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<DataBaseContext>(opt =>
                opt.UseSqlServer("DataBaseContext"));

            var config = new AutoMapper.MapperConfiguration(c =>
            {
                c.AddProfile(new MapperProfile());
            });

            var mapper = config.CreateMapper();

            services.AddSingleton(mapper);
            services.AddSingleton<IUserService, UserService>();
            services.AddControllers();
        }

        //some code
    }
}

This is someproject.csproj:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="AutoMapper" Version="10.1.1" />
    <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="5.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="5.0.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.1.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.11">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.4" />
  </ItemGroup>


</Project>