I have a .NET 8 Blazor App. I want to use OData for CRUD. My database is code first, created with migrations.
For the following model:

public class Category
{
    [Key]
    public int Id { get; set; }
    public string? Name { get; set; }
    
    public ICollection<Expense>? Expenses { get; set; }
}

And the following DbContext:

public class MoneyMachineDbContext : DbContext
{
    public MoneyMachineDbContext(DbContextOptions<MoneyMachineDbContext> options) : base(options)
    {
    }

    public MoneyMachineDbContext()
    {
    }
    
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        
        modelBuilder.Entity<Category>()
            .HasMany(c => c.Expenses)
            .WithOne(e => e.Category);

        modelBuilder.Entity<MonthReport>()
            .HasMany(mr => mr.Expenses)
            .WithOne(e => e.MonthReport);
    }

    public DbSet<MonthReport> MonthReports { get; set; }
    public DbSet<Expense> Expenses { get; set; }
    public DbSet<Category> Categories { get; set; } 
}

And the following Restier configuration:

builder.Services.AddDbContextFactory<MoneyMachineDbContext>(options =>
    options.UseSqlServer("Server=localhost\SQLEXPRESS;Database=MoneyMachine;Trusted_Connection=True;Integrated Security=true;TrustServerCertificate=true;"));

// Configure Restier OData
builder.Services.AddRestier(apiBuilder =>
{
    apiBuilder.AddRestierApi<EntityFrameworkApi<MoneyMachineDbContext>>(services =>
    {
        services.AddEFCoreProviderServices<MoneyMachineDbContext>((serviceProvider, options) =>
        {
            options.UseSqlServer("Server=localhost\SQLEXPRESS;Database=MoneyMachine;Trusted_Connection=True;Integrated Security=true;TrustServerCertificate=true;");
        });
        services.AddSingleton<IChangeSetInitializer, DefaultChangeSetInitializer>();
    });
});

...

app.Filter().Expand().Select().OrderBy().MaxTop(null).Count();
app.MapRestier(routeBuilder => routeBuilder.MapApiRoute<EntityFrameworkApi<MoneyMachineDbContext>>("odata", "odata"));

I try to add a row to the Categories table with Postman:

1. First Try
   POST https://localhost:44372/odata/Categories
   Body 1:

{
    "Name": "Guilty Pleasures"
}

I get 500 internal server error: “Object reference not set to an instance of an object.”
Same error with Body 2:

{
    "Name": "Guilty Pleasures",
    "Expenses": []
}

2. Second try
   with body

{
    "Name": "Guilty Pleasures",
    "[email protected]": null or [] or {}
}

I get 400 bad request: “A POST requires an object to be present in the request body.”

However, the post request worked when using an action with Body 1 from First Try:

[HttpPost]
public async Task<IActionResult> AddCategory([FromBody] Category category)
{
    context.Categories.Add(category);
    await context.SaveChangesAsync();
    return CreatedAtAction(nameof(GetCategory), new { id = category.Id }, category);
}