@{
    var galleryImagesJson = System.Text.Json.JsonSerializer.Serialize(new[]
    {
        new { url = "/images/microsoft.svg", text = "Microsoft Logo" },
        new { url = "/images/Intel.svg", text = "Intel Logo" },
        new { url = "/images/sample-photo.jpg", text = "Sample Photo" }
    });
}

<richtextbox
    name="galleryImagesEditor"
    toolbar="default"
    height="300px"
    gallery-images-json="@galleryImagesJson" />