How to filter unwanted text?

I would like to filter out the word “WTB” from my results. Right now I get notified of any changes but would like to stop getting notified if said word is anywhere.

Welcome to the forum @harrypotter!

If you want to get alerts only when the text “WTB” is not present in the new text, then you can add conditions like:
Added text -- does not have -- WTB.

Apart from conditions, in case you have not made de-selections on the page, you should consider de-selecting timestamps and other such unwanted texts.