how to add HTML content in topics

[Rae]

I am new to NodeBB. I have a database it contain HTML, and I wanna build a forum from that database.
The thing is, NodeBB does not allow HTML, and it's not possible for me to convert that HTML to MarkDown because it contains HTML tags such <abbr> <iframe> also some tags have class and id.
I think I have similar issue like that in that topic https://community.nodebb.org/topic/12081/restrict-creating-new-topic-and-blocking-html-posts-for-users
Please help! Is there any way around this?

[julian]

Use of the Markdown composer is optional, and you can save HTML directly into the database, and this is what is used for other composers like Redactor. Still other composers (Quill composer) save content into the database in their own special format.

Markdown is not meant to be activated for either of those.

Alternatively you could allow HTML in the markdown settings, but I would highly advise you also install sanitizehtml plugin, otherwise anyone can post anything including malicious scripts as a post in your forum!