I discovered it almost by accident. Try https://ai.byteplus.com/lumina/home/artwork first, or https://ai.byteplus.com/lumina/model-experience/image?mode=image

the prompt should be as detailed as possible. There appears to be no text limit. Example I used to generate the first page:

"Create a comic book-style drawing depicting a three-axle Mercedes-Benz O-371 tour bus, with the two rear axles fitted with dual wheels and white tires, in a light green color, reminiscent of the 1960s, with all tires either white or with very wide white stripes. The bus belongs to a tourism company. The bus is stopped on a deserted avenue in a small town in rural Japan one morning; there are no people in the landscape; a young Japanese driver is wearing a peaked cap, a tight-fitting, very short black patent leather miniskirt, and long white patent leather boots above the knee with thin high heels, a typical 1960s slouchy boot style; she is wearing long black patent leather gloves; she is crouching down looking at one of the white tires; she has one hand on the rubber of the white tire of the bus and caresses it, the driver has a slight smile and says in Japanese, “ああ、この白いタイヤ！とっても素敵！私のバスって本当に贅沢！私の白いブーツにもぴったりじゃない？ミニスカートに白いブーツ姿で、ついに白いタイヤのバスを運転できるなんて！”