getting insurance for 高額療養費

If I understand the system correctly, it is something along the lines of that the insurance company cover the specific months where the sum exceeded something like 80 000yen ish per month (depends on you salary)...

https://www.kyoukaikenpo.or.jp/g7/cat710/sb3160/sb3170/sbb31709/1945-268/

So this happened twice last year that the sum exceeded this in 2 particular months. And the insurance company 全国健康保険協会 sent a pre filled in form for the first of these months. On the form i think it it says to only do one month a form. But they didnt sent a form for the second month, which was way more expensive by the way.

Anyone done this for several months? How to do this? Can i do both months on the same form or how to get another form?