Default value to textarea in .net core MVC

<textarea asp-for="Description" class="form-control">@ViewBag.Product.Description</textarea>

<textarea asp-for="Description" class="form-control">@ViewBag.Product.Description</textarea>

Based on the example above, I want to add a default value to the textarea since it is a page for user to update the item.

Default value to textarea in .net core MVC - C#