I was unable to find any specific information regarding a series or text titled authored by " ."
The "extra quality" tag refers to the enhanced art style and detailed panels in this specific installment. back door connection ch 30 by doux extra quality
You can find the series and the latest chapters on official platforms: Lezhin Comics: The primary official platform for many of Doux's works. Tappytoon: I was unable to find any specific information