Ascending or descending digits, to a typographer, means these letters:
bdfghjklpqt
These digits, or letters, extend above (ascending, or ascenders) or extend below (descending, or descenders) below the type line. They all have extensions that go up or down.
Digits, or letters, that are not ascending or descending are what's left, namely:
aceimnorsuvwxyz.
You need a password that is made up of non-ascending or non-descending characters.