You don't!
You don't have to apply for Grades at all. Graded membership is entirely optional and each level requires that the member testifies to having accomplished the required knowledge and actions for that Grade.
You do not enter Second Circle if you have not testified to having proven that Lifeforce Vampirism is real. You do not enter into the Third Circle if you have not testified to having proven that the Undead Gods are real. You do not enter into Fourth Circle if you have not testified that Magic is real. You do not enter Fifth Circle (Adept) if you have not testified that the Inner Self (the Dragon) is real.
Members enter higher Grades because they want to be able to communicate openly with others whose experiences they now understand to be real. It is the same reason graduate students in physics will prefer to discuss their studies with professors rather than grade school teachers ...or grade school students.