"Your father wants you to make tea."
Translation:Baban çay yapmanı istiyor.
I'm not sure who posted the comment you saw, but that's not really true. "istemek" doesn't need the accusative case if the 'wanted' word is an infinitive verb, or a general/unspecific noun. Here are some Duo examples:
- Öğretmen olmak istiyorum. = I want to become a teacher. (link)
- Bu ülkede barış istiyorum. = I want peace in this country. (link)
However, if we use "istemek" with a specific noun, including verbal nouns/gerunds, it will need accusative case: