Modal Service Not Working

[ncveggm]

I try to use Modal Service and follow the instructions in documentation but the modal not shown
this Home.razor
@page "/"
@using BlazorBootstrap
Home

Hello, world!

Welcome to your new app.

<Button Color="ButtonColor.Dark" @OnClick="() => ShowModal(ModalType.Dark)">Show Dark Modal

@code {
[Inject] ModalService ModalService { get; set; } = default!;
private async Task ShowModal(ModalType modalType)
{
var modalOption = new ModalOption
{
Title = "Modal title",
Message = "Modal body text goes here.",
Type = modalType,
};

    await ModalService.ShowAsync(modalOption);
}

}

I register service in program.cs

builder.Services.AddBlazorBootstrap();

add the links of css and js files in app.razor

<script src="_content/Blazor.Bootstrap/blazor.bootstrap.js"></script>

in MainLayout.razor I add
in the last of page

but the code not work