This extension method is a workaround to manually trigger a submit events of an EditForm component. Taken from EditForm.HandleSubmitAsync() private method.

EditFormExtensions.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Components.Forms;

namespace FluentGuru.AspNetCore.Components.Forms
{
    public static class EditFormExtensions
    {
        public static async Task SubmitAsync(this EditForm form)
        {
            if (form.OnSubmit.HasDelegate)
            {
                // When using OnSubmit, the developer takes control of the validation lifecycle
                await form.OnSubmit.InvokeAsync(form.EditContext);
            }
            else
            {
                // Otherwise, the system implicitly runs validation on form submission
                var isValid = form.EditContext.Validate(); // This will likely become ValidateAsync later

                if (isValid && form.OnValidSubmit.HasDelegate)
                {
                    await form.OnValidSubmit.InvokeAsync(form.EditContext);
                }

                if (!isValid && form.OnInvalidSubmit.HasDelegate)
                {
                    await form.OnInvalidSubmit.InvokeAsync(form.EditContext);
                }
            }
        }
    }
}