Is there a viewer plugin available for Canvas Draw?
If there’s a preview handler for it that works in File Explorer’s viewer pane then it should also work in Opus’s.
It’s not a program I’ve heard of before, and I’m not sure I found the right one via Google.
They used to have something called "Canvas X View", but I don't know if that included a preview handler that would work in other software, and it seems that they've removed the website for it.
In general, if it's a proprietary file format only their software uses, you'd need to ask them if they provide a preview handler or plan to.