Dyson soft roller head?

The best way is always to buy directly from Dyson. I am not sure which model you own, but there are different versions of the soft rollers and some may not compatible to your vacuum. I find it bit confusing to search for the parts on their website.. so it is best to call them or use their online chat. Dyson gives you a family discount (I believe 20%) if you previously purchased Dyson products and registered them online (but not their newest machine). The reps sometimes say the discount doesn't apply to the parts, but just ask them to check again, because I received my 20% in the past.
HOWEVER, there is a major shortage of Dyson products since Covid, and the chances are Dyson Canada doesn't have the soft roller you are looking for.. in which case you will be asked if you want to receive an email notification when it is available.. and YMMV how long that will take.
Another option is to look for the soft roller from your local Craigslist or Kijiji. Sometimes I see people selling it in like new condition because they never use it. But again, check the model compatibility with Dyson rep first.

Hi OP, did you find a soft roller head already? I'm also curious to see where they are able to be purchased.

If yours is making a lot of noise, there's a good chance that something is stuck inside causing that noise. Just take it apart (there are tons of videos how), clean out the dust and maybe apply a bit of lubrication to the moving parts.