Convert date format in plain text "APR 1, 2021" to "YYYY-MM-DD" ?

If you're trying to convert a plaintext date like "APR 1, 2021" into an Appian "Date" type object, you'll probably need to concoct something yourself (though if you spend a few minutes searching old posts here you'll probably find code pre-written for you).  To convert a Date object to "yyyy-mm-dd" format, you can simply use the "text()" function, like "text(local!date, "yyyy-mm-dd")".

You need to cast it from Date Type to Text. There are different ways to perform casting.
https://docs.appian.com/suite/help/22.1/Casting.html please find here.

please go with >> datetext(now(), "yyyy/MM/dd"). this will help i think. Just replace now with whatever and however you want