[NTG-context] Deleting The Blank Before Chapter Titles

Hi, I am customizing my chapters’ style. However, I cannot delete the blank before the printing of chapter titles. I tried: \setuphead [chapter] [before={}] \setuphead [chapter] [before={\blank[none]}] \setuphead [chapter] [before={\blank[back]}] but they do not work. Thank you, Best wishes, Joas.