help please 🥺 what should be inside the envelope to request koseki?

It’s my first time to request a koseki tohon and I’m having trouble to know what to write and put the paper (request form for koseki).
I’m from Saitama but I have to request it from Saga (since my koseki is from Saga). I already have the request form for the koseki, already paid ¥450 at the post office, already got the stamp.

Should I write my address at the envelope and should I put my My Number Card inside (proof that it’s me) or my passport?
Should I also write the address of the city hall in Saga at the envelope?

I tried asking a lot of staffs here in Saitama city hall (used a translator app so I can explain all of my questions) but they told me to look at the Saga City Hall website which I did but couldn’t find anything. I also tried looking it up online but there’s nothing.

Sorry if there’s a lot of “should I” it’s cause I really have no idea and I’m having a hard time 😭. Thanks if someone answer!!