Table of Contents from epub to mobi

I know this has been answered somewhere in the forums and if I can be directed to the answer that is just fine.

I have an epub ebook that does not have a table of contents. I have added a table of contents using calibre and the edit TOC feature. It works fine. When I convert using the convert feature to get it to mobi, my table of contents is not in my book when I open it on my Kindle.

I am a huge novice when it comes to ebook editing. I just want to add a TOC.

Thank you for any help or direction.