Now, if you want to be prepared in an institution, you must pass the exam, otherwise you will not enjoy the treatment of the unit without preparation.
And to put it bluntly, many people can do cleaning, and they can change at any time, without any education or preparation. We have never seen a person who does cleaning work become a formal employee of an organization, even if he does cleaning work for the leaders of the organization.
So we should be soberly aware that this job is only a stopgap measure. When there are good job opportunities and hopes in this organization, it is wrong to jump right away.