Greetings @KERICEDOR ,
Thank you for posting on the Instructure Community!
From what you're explaining, this appears to be an issue with Khan Academy's integration itself, and not something specific to Canvas. I recommend reaching out to your school's IT / Canvas team to investigate this issue to ensure everything is configured correctly for your school. However, it may also be a good idea to reach out to the support team at Khan Academy, too, as they will be able to assist you with getting this working better than members of the Instructure Community.
I hope this helps, all the best!
Noah