Flashcards embedding issue

I have a main page “Dashboard” titled ‘Flashcards spaced repetition’, which embeds pages that have Flashcards.
The embedding creates a useful button “Review cards”, however 2 embeds are problematic.
Challenge 1: {{Cards [[French metiers]]}} shows this exact text highlighted in browny/yellow, what does that mean?
Challenge 2: {{ Cards [[French useful words]] }} shows the [[ and ]] greyed out and is not embedding and making the useful button “Review cards”.

Solved by typing {{cards [[pageName]] }}