If we have to say the difference, the main difference lies in the difference in purpose. The purpose of practicing Dan Dao is to become immortal. First, we need to make Inner Dan, and then turn it into a treasure. Finally, Shen Yuan will be out of body experience and become immortal, so as to achieve great magical power. However, because the cultivation conditions of alchemy are harsh, it seems that people who become immortals in real life have only heard of it and have never seen it. Later, people found that people who practiced alchemy lived a long and healthy life. Gradually, people no longer pursue immortality, but instead pursue health and longevity, so they learned some techniques from Dan Dao and combined with some effective fitness methods in life to improve it, and finally formed the present Qigong. At this point, the achievement method of Tibetan tantra is particularly obvious. You want to become a Buddha, this is what you want to practice, and so is health and longevity.
There are many books about Dan on the Internet, such as Xian Xue in the late Qing Dynasty, Hu Haiya's Modern Xiandao Health Book in China, Ancient Zhouyi Shentongqi, Rootless Tree and so on.
The question now is not whether there is any achievement method, but the key lies in temperature loss. There is a saying in the circulation of Dan Gong: Pass on merit but not fire. It means that I can pass it on to you at a glance, but I won't tell you the temperature inside. Unless you are a disciple who inherits the mantle, you will get advice on practicing temperature.
Because everyone handed down will be warned not to reveal the secret of Dan Gong without authorization, which is the most serious thing in ancient times, but some people want to spread it. Therefore, it will be expressed in various obscure languages in his books, which also makes the "Dan Jing" obscure.
Therefore, even if you get Dan Shu, you may not be able to understand it. Secondly, you don't understand the conditions of practicing alchemy (money, partners, law, land). In modern times, you don't want to practice by yourself. So learn qigong realistically, but Dan Gong's books can really be used for reference when practicing qigong.
If you really want to achieve something, you can practice tantric techniques, but you must learn from your teacher. You can't practice it by yourself. There is a saying in Tantric Buddhism: You can't learn without the permission of the teacher, which means that the Tantric techniques you practice must be approved by the master or mage. Even if you find the same technique from the Internet, you can't practice it without the master's permission.