Hi @HENRYFOURNIER,

This is apparently a known issue at the moment.  The  [OPEN] Apple iWork files are not rendering in Spee... - Instructure Community - 627577  page gives a little more detail, but there doesn't appear to be a workaround for this right now.  Even though it's a known issue, I'd still suggest reporting it to Canvas support to help them judge the impact and so that you'll be notified when the fix is in place.

I hope this info helps!

-Chris