1-20 (institution) submits relevant materials to the window of the pension service hall on the second floor of the Social Security Bureau and goes through relevant formalities.
Generally, three months before retirement, retirement procedures should be prepared. As for retirement procedures, you can go through them three months in advance, because the procedures are really complicated and there may be some problems in your file. If you have more time in advance, you will have time to supplement the information. If you are short in advance, you may be passive when information is scarce.