It doesn't appear the option from the menu
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Just checked and confirmed that CDTs don't seem to be available in the new community edition They probably decided to exclude them since you can't apply security on a CDT.
I'd almost assume it has more to do with the fact that we don't have direct access to the DB there, so it would be difficult to manage CDTs, prevent naming conflicts, make retroactive column changes, or various other things along those lines that sometimes or always require direct DB access?
Thank you very much for your response. This is the answer I got from Appian itself.