The best place to write an infinite novel was probably your own writing platform, such as Qidian, Genesis Chinese Network, etc. These websites had a rich readership and writing resources that could help him promote his novels to attract more readers. He could also publish the novel on other online writing platforms or blog sites such as wikipedia, jianshu, douban, etc. These websites had a large number of readers, which also allowed their novels to gain more exposure. Other than that, he could also consider posting the novel on social media platforms such as WeChat, Weibo, and TikTok. These platforms had a huge user base that could help him promote his novels to more readers.