In short, I would like to ask, if it would be possible to initialize TinyMCE inside dynamicly created iframe. It looks like TinyMCE was initialized, but the events not working

I'm trying to add TinyMCE with inline mode on my site. I have to use inline mode because only this mode supports fixed_toolbar_container. The toolbar has to be placed on top of page. TinyMCE will be used to edit content in back office and then content will be displayed for regular users. I have to load custom CSS into TinyMCE to have for example proper color for header, but I don't want those styles to affect the back office. I tried to create a dynamic iframe in back office create a content a toolbars containers inside, but it looks like something is wrong, for example I can't select text and use Bold style.

I have code example: https://codepen.io/gregwi/pen/bGLZpvx

In the code above:

1. Creating a sanbox iframe element (other iframes modes didn't work too for me)
2. Add container and toolbar containers to iframe
3. Define configuration for tinyMCE. Configuration use elements from iframe as configuration for TinyMCE
4. Initialize the TinyMCE