Trying to insert an mp4 file , but does tell me this is not accepted format

Hi beate, 

Thanks for reaching out! Sorry to hear you are having difficulty inserting your MP4 file. I understand how frustrating that can be. 

I see you've opened a case and you're working with my colleague Renato. You're in great hands!

We'll continue the conversation over in the support case. 

Have a great day and happy developing! ✨