Add a new note using "Cloze" notetype, without any cloze deletions ({{c1::example}}) on the note.

See the card on the study screen or on the preview of the card browser.
A translated alert message is displayed, as it is on Anki Desktop (as follows)

The untranslated alert message, "Please edit this note and add some cloze deletions. (help)", is displayed.

translations are in crowdin.com - if you don't have access Tim is the man
@snowtimeglass is a regular translator on crowdin, he's trying to say that the string is not on crowdin, it seems to be hardcoded into Collection.java
Ah - I see. I've certainly seen their contributions, I guess with the detail on some I was surprised it wasn't a link tot he code line - apologies @snowtimeglass
Doing my best to triage some of the stale issues in the tracker but I'm all too human...
Thank you always, @timrae @mikehardy
Take your time!
I wish they were all that easy...
Most helpful comment
@snowtimeglass is a regular translator on crowdin, he's trying to say that the string is not on crowdin, it seems to be hardcoded into
Collection.java