As for the tripartite agreement, that thing will be useless in the future. But it is essential when I just graduated. The school uses this to count the employment situation of students, and the company uses this to threaten you, for fear that you will break your promise. So if you don't give the new company a tripartite agreement, he will be worried that you will deliberately hold it back and plan to change it later. So he won't dare to sign a contract with you.
We have also reported the loss of the tripartite agreement and asked the school to reissue it. But this procedure is very troublesome and mainly related to the guide. It is a good thing that he is willing to help.