h5p messages and buttons translation

Hi. I need to translate basic messages and buttons of h5p quizes. Not to translate h5p plugin , but messages of every quiz such as "Check", "Next", "Show solution" and so on. I can traslate this inside every quiz, but I have about 200 quizes and it's a huge amount of work to translate every message and button for every quiz. I tried to understand how to resolve this problem from h5p.org. There are files with json extension for every type of quiz and every language. For example fr.json for question set quiz type. However I don't understand how to use them.  Could you please help me. Thank you.