To customize the UI,
You can replace the current view with a new one. This is a customized account view: Create a file named Default.cshtml and put it in the folder Acme.BookStore\src\Acme.BookStore.Web\Themes\Lepton\Layouts\Account
@using System.Globalization
@using Microsoft.Extensions.Localization
@using Microsoft.Extensions.Options
@using Volo.Abp.AspNetCore.MultiTenancy