HTML code does not work in FLARUM

Hello!

I work with .NET, and I’m facing an issue that has been discussed multiple times here: HTML tags are treated as plain text in Flarum.
In my case, I just want to use simple lists or tags like <sub>, <sup>, or <br> for chemistry formulas, but I can’t find a way to overcome this problem. In the actual posts created in my forum the HTML tags are visible as part of the text, the actual effect is not being applied.

How did you handle this issue in your own cases?

Thanks!