Most of the companies do not have their 2023 catalogues up yet.
Adelman s does ship to Canada but you need to pay for a phyto sanitary certificate which is about $100. And shipping is expensive too. And there is exchange on the money plus they charge duty.
And don't order at this time of year as they sit waiting for Customs processing.
Many companies do not sell every peony variety every year.
Some appear to offer different ones in alternate years.