In this case, the upper age limit for enlistment is 22, of course, based on your household registration book and ID card.
You mentioned "no need to go to school"
In one case, your studies are only in the internship stage, and the school agrees to treat you as an internship, so you can apply at the end of 10 one year before graduation, and then get the diploma the following summer.
Another situation is that you signed up for the "pre-enlistment" of fresh college students around May of the year of graduation, returned to your hometown after graduation, and then joined the army with the recruits recruited from the society around 1 1. In this case, tuition fees can be refunded according to state regulations, and the age can be relaxed to 23 years old.
These are all conscripts.
There is another situation, that is, the army has a number of specially recruited non-commissioned officers among the fresh graduates of your major in your school. Generally, it is also registered around May and passed the medical examination and political examination. According to the graduation employment procedure, they started as non-commissioned officers and joined the army around August. Although the treatment is not as good as that of an officer, it is much better than that of a conscript.
This opportunity is rare.