The code is as follows:
<iframe src="http://player.bilibili.com/player.html?aid=38882703&cid=68339355&page=1" scrolling="no" border="0" frameborder="no" framespacing="0" width="500px;" height="500px" allowfullscreen="true"></iframe>
<iframe width="560" height="315" src="https://www.youtube.com/embed/9t-GF_f7eIY" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
Display failure in bootsnote
ps: Console has no information output

Display normal in index.html

Please change your setting in Interface tab. In preview section change the Sanitization to Allow dangerous HTML tag.
Most helpful comment
Please change your setting in Interface tab. In preview section change the Sanitization to Allow dangerous HTML tag.