Potion Lab key – Winx Club Butterflix Adventure Review

It’s impossible to get the get the key is in the Potion Lab room. I got the one in the history of Magic’s room and all the other keys except that. How do I get it? The game took all my blue and pink diamond I now have none left. I worked so hard to get them. Please Help me. Please
Review by sid friend on Winx Club Butterflix Adventure.