Can you actually log in as the Task Runner user, or does your authorization system require that all users be generated outside of Canvas to authenticate? If you can log in as the Task Runner, try creating a password and logging in to Canvas as the Cidiscape Task Runner for Cidiscape authentication. Then, reopen cidiscape.ciditools.com, log out of Cidiscape, and log back in.
Do you have an SSO platform that handles authentication? This may be preventing you from authorizing Cidiscape through the task runner user.
If you are unable to use the workaround above, please reach out to support@cidilabs.com for assistance. Any additional information about your authentication process might be helpful in tracking down the issue.