There were two kinds of Alchemy Masters. One had official credentials, while the other was essentially a wanderer.
In the pill refining world, there was only Origin Pill Palace. Origin Pill Palace was the holy land for alchemy cultivators, and ordinary alchemy cultivators did not even have the qualifications to learn anything about it.
Thus, the Pill Palace had become the temple for alchemy cultivators. If you wanted the credentials of an Alchemy Master, you would have to go there to be examined.
They had special alchemists specialized in performing those trials. Once you passed, you had two options: one was to join the Pill Palace, becoming one of its members, and enjoying the luxurious treatment of a disciple of the Pill Palace.
You could also choose to leave. The Pill Palace would grant you a Alchemy Master's status tablet, and each year the Pill Palace would distribute a certain amount of resources to you.