This word was not introduced at all yet (I am still in the script basics section), and yet it is asking me to translate the word 'one' into Hindi. I'm not sure if this is an error or just weirdness in how the program works, but it is very confusing.
Also there is no audio for the word.
There is a button to report an error, but the three multiple choice error options do not fit this particular problem.
If you are using a mobile device, go into the keyboard settings and enable Hindi as one of your languages (you would prabably need to download it first). If you are using your desktop, you could use an online keyboard and paste in what you typed. A general search should bring up a decent one, but here is the one I use:
Alternatively, instead of adding a Hindi keyboard layout from your windows options and using a cheatsheet you can download a chrome extension called DuoKeyboard which does the same but adds a neat cheatsheet under the answer box https://chrome.google.com/webstore/detail/duokeyboard/dekooljcgfaiokofbciaflklkfniimfa
The report options are generally:
"[ ] The audio does not sound correct. [ ] The dictionary hints on hover are wrong or missing. [ ] The Hindi sentence [or English sentence] is unnatural or has an error. [ ] The "Correct solution" is unnatural or has an error. [ ] My answer should be accepted."
...with some of the answers not shown if they're not applicable to a question and depending on whether you get the sentence right or wrong.
As you say, there's no freeform "other" option, at least on desktop.
Note to the mods who watch the chat channels occasionally:
I noticed an error on one of the multiple choice questions that does not provide a way to report that type of error. So, I arbitrarily picked this question, reported it (flagging all choices for what is wrong) and am adding this comment.
Type of question: "What do you hear?" with four choices. On this question, if "i" (short i as in "किताब") is one of the wrong answers, the audio sample for "i" is wrong. It sounds more like an English long i as in "find".
Not too big a deal because when "i" is the correct answer on this type of question, the audio used for both the prompt and the right answer is correct. This is only a problem for beginners who might be learning the sounds of the language by clicking all the answer buttons and listening to the sounds made, and the sound given for "i" in this situation is not one of the sounds of the Hindi language.
The "What sound does this make?" type of question is unaffected as you don't get audio feedback on any of the choices you make. And the 'Select the correct character(s) for "i"' type of question is also unaffected - i.e. if "i" is one of the wrong answers, at least the audio is correct for "i".
And as noted, if "i" is the correct answer for a "What do you hear?" question, the audio is also correct in that case.
Just thought you'd like to know. :-)