@page "/test1"

@((MarkupString)@block)

@((MarkupString)ShowHtmlBlock())

@code { string block = "

Test1

private string ShowHtmlBlock()
{
    return $@"</iframe width=""1024px"" height=""768px""><image width=""1024px"" height=""768px"" src=""https://p1.pxfuel.com/preview/653/702/399/rose-flower-flowers-red-rose.jpg"" allowfullscreen /></iframe>";
}

}