Hello...  I'm not sure how you actually integrated the HTML editor you're trying to use, but it most often is as easy as adding two lines of code to your front end, to start with.  The example below is from the open-source FAQ module.  

Code Example (web forms)

<%@ Register TagPrefix="dnn" TagName="TextEditor" Src="~/controls/TextEditor.ascx" %>
<dnn:Texteditor choosemode="False" controlid="teAnswerField" height="300" id="teAnswerField" runat="server" width="600">

Old Documentation:  https://www.dnnsoftware.c.../text-editor-control

If you're using a SPA approach, then I'd recommend using DNN Elements instead.  

Demo:  https://dnncommunity.gith...ments-richtext--docs

Thanks for your reply, this is same what I used, I will check DNN Elements.

Oh, and I used to include TinyMCE in some of my modules, because it's so good and easy to implement.  But, when you do things like that, you should know that you lose the power of the configuration/integration of the method we've already discussed here.  Also, that specific editor is no longer compatible with the MIT license that DNN is shipped under, since they're GPL2+.