Don't know why this question is "Assumed Answered". At least not in this forum.
One way around this problem—text hyperlinks are not supported by FXL EPUB—is to create buttons on top of the text that do the hyperlinking.
Caution: Do not anchor the buttons, that would not work. Just place the buttons on top.
If you search the web, you might find an ExtendScript script, that is able to do this tedious job for you.
Moved to InDesign EPUB forum
We have index page of any book and I want.to click on particular topic
then it will on that page where it start. That's I want to do..
If not yet answered. Create a text anchor (New Hyperlink Destination > Text anchor) in the content, where the reader should land after tapping the link. In the index, select the word you wanna have the link and create a "New hyperlink" and "Link to" this previously created "text anchor".