Can´t create an html table of contents on Sigil

Hi guys! Im having some trouble creating an html table of contents on my Sigil 0.4.2.

I know you must click on "tools", "table of contents" and then "generate table of contents" but I just don´t have that option! When I click on "tools" I just see "Meta editor", "validate epub" and not much else :blink:

HELP PLEASE!

Thanks!