LTI Authenticator w JH error 405 : Method Not Allowed

Setting up with canvas using the LTI authenticator. I’ve configured it in my jupyterhub_config.py

POST for launch url is working (302) but getting these responses now:

GET https://jupyter.host.ca/hub/lti/launch?next=%2Fhub%2Fhome: 405
POST https://jupyter.host.ca/hub/security/csp-report: 403

Anyone else get this working or see this error?