Previous Application for COE's document

Hello,
I've been in Japan before for technical intern training and I have return to my country.
Now I want to enroll an internship in Japan again, and my agency said they need my previous Application for COE document. I have asked my previous company where I did my TIT back then but they said the document is no longer exist.
My agency said that japan immigration bureau might decline the application without my previous document since I totally forgot what I wrote there back then.

Please tell me if there's a way to get my copy of my previous zairyu shikaku nintei shomeisho koufu shinseisho

"My agency said that japan immigration bureau might decline the application without my previous document since I totally forgot what I wrote there back then.�h

immigration will check your new application whether it is coincident with the old one or not, especially on the points of your histories of job and education.
thus, when you got an old visa with a fake history, you have to write the same fake history. but, many applicants forgot what they wrote as being fake. (that is the reason why the new agency ask you the old application documents. you don't need to add the old documents to a new application. immigration has your old application. you are tested as you are honest or not.)

the sad stories are that you wrote your history as being honest, but, the old agency changed your history to satisfy a visa requirement, and you don't know this fact.

I see. Thank you very much for the answer 🙏🙏