Add youtube video in description / Change slug

Hi !

I would like to add a video from youtube, directly in the event page. Is it possible ?

– I try a simple iframe in WP Editor field -> Hmtl disappear (can we change that to accept html?)
– I try a Shortcode from my theme. Accepted but doesn’t work
– There doesn’t seem to be a special field to embed a video (except the button/link to the video on he right)

Also, can we change the slug for single event page ? I have some special letters (é è), but i can”t change them ??

Can you help me please ?

Thank a lot !

The page I need help with: [log in to see the link]