[Biashpainabix]

Salaam. my query is about on a person who misses both intentionally (he acknowledges it as a sin) /unintentionally. that person who missed salah intenianlly/unintentionally said Allah forgives everything. Therefore if he makes qadah, for the recent salah he missed, does it appl to all the salah that he ever missed? or can he be forgivven for that?

also is it true that missing salah is unforgiveable?