I just don’t think it was ever implemented.
Type answer boxes will not be displayed when you review your cards on ankiweb.net.
– Field Replacements - Anki Manual
Sure, if you add some other sort of text input field that persists to the other side of the card and lets you compare you answer on your own, I have no reason to think that wouldn’t work on AnkiWeb. I’ve never tried it myself, but a few solutions that others have offered for that:
- Field for typedAnswer on answer card - #2 by hkr
- Some questions/thoughts concerning the answer field - #4 by FrankJH
- Element which stores the solution typed by the user - #17 by Eltaurus
- Reddit - Dive into anything - type answers without automatically comparing
- Reddit - Dive into anything - built-in notepad