The key here will be turning the input’s value from one text value that contains many words into a list of individual words. You can do this by using the “split by” operator to split the single texts into a list of texts using a “space” character as the divider between words in the list.
From there, once you have a list of words the user typed in, you can compare this list to the list of banned words using the “intersect with” operator. The expression for your comparison would be
Multiline Input's value:split by ( ) intersect with do a search for banned words:each item's words:count > 0
I hope this helps!