I have trouble with CANFD using Python on a Raspberry Pi 4 B. Last week I have tried to install and test CANFD using Pyton.
I was able to initialize CAN as you can see here:

But opening CANFD failes with parameter error:

I have followed your gide from:
viewtopic.php?t=3381
But i used newest Buster version:
Release date: May 7th 2021
Kernel version: 5.10
Could you please help me. What I am doing wrong?
Best regards