How does Saint ol switch to Sagittarius, Virgo, etc?

When the character reaches level 79, there is an advanced professional task, in which Tianma becomes a shooter, a fairy becomes a virgin, Bai Niao becomes level 1, a phoenix becomes a lion, a dragon becomes a Gemini, and a dragon becomes a Libra. You can also switch to other professions through the guardian constellation, and then advance. There is no limit to the number of switches.