In the explannation above, it says:
"To express lacking [something], you will use manquer de or d' + [thing].
You do not need to use the partitive articles (du, de l', de la, des) here, just as you wouldn't say I lack thesugar but simply I lack sugar:"
It's a bit confusing because then all the examples use "de". You really have to your know your grammatical terms! I wonder if it would be clearer to say:
"You do not need to use the definite articles (le, l', la, les) here".
Just a thought.