Index.cshtml

@page
@model IndexModel
@{
    ViewData["Title"] = "Home page";
}
<div>
    @Model.Message
</div>
<form method="post">
    <div class="form-group">
        <label asp-for="UserName" class="col-form-label col-md-2"></label>
        <div class="col-md-10">
            <input asp-for="UserName" />
        </div>
    </div>
    <div class="form-group">
        <label asp-for="Password" class="col-form-label col-md-2"></label>
        <div class="col-md-10">
            <input asp-for="Password" />
        </div>
    </div>
    <div class="form-group">
        <button class="btn btn-outline-primary btn-sm">Log in</button>
    </div>
</form>