How to highlight text already HTML rendered in Markdown that maps correctly with the raw Markdown text?

Hi,

I'm beginner in React so my question might be phrased incorrectly. What I would like to do is create the ability to add highlight to text that is already rendered in Markdown so the the user can add notes to the highlighted text.

User flow:

- Page loads with Markdown formatting.
- User wants to add a note on a title, selects the title.
- It turns the selected text into yellow highlights like in a Acrobat.
- Then a modal opens where the user can add notes,
- User can then click back on the highlighted title and open the note again.

I'm using react-markdown. I googled for a solution but I'm not getting any results.

How can I get it to highlight different markdown elements?

Thanks in advance.