How to write the social security application?

Dear company leaders:

I, XXX, joined the company as XXX in XX, XXXXX, and I am honored to be affirmed by the leaders and formally become a member of XXXXX Company. First of all, thank the company leaders for their training and help. At the same time, the company's harmonious and good working atmosphere and the prospect of the company's continuous development and growth have made me cherish and love this job more, hoping to work here for a long time. In order to work better and avoid worries, I hereby apply for social insurance from the company. I hope the company can approve it, thank you!

Applicant: year month day.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.