If you have to write an application for quitting the league, you usually need to write your name, class, gender, major, club name, contact number, reason for quitting the league and application time.
One of the most important reasons is to quit the league. The reasons for quitting the league generally need to be sufficient. There are generally word requirements, which are basically thousands of words. But in my opinion, it is no problem to write a few hundred words. The club won't let you go unless you are in a higher position in the league and must write thousands of words. If the reason is not sufficient, the club won't let you go. After all, you are not an ordinary member of the club.
If you don't write an application for quitting the league, similarly, if you are an ordinary league member, the league will eliminate you according to the rules of the league. If you have a position, the teachers in charge of the league and the heads of clubs will talk to you one by one, ask how you are doing, and finally advise you not to quit the league. If you want to quit the group, you have to write an application for quitting the group.
In short, whether or not to write an application for quitting the league and how to write it depend on your personal importance to this club.