What does 'JWT must have 3 parts' mean?

I have mostly figured it out. I had my settings wrong. I started Auth0 with a slightly different auth flow. You used to have client id and secrets and all that stuff. I remember the email a while back about this changing. Everything is working accept my api (.net core) is not sending ‘access-control-allow-orgin’ headers on the actual get requests (is on the optionis call, weird). The bearer token (from ‘access_token’) now looks correct when using jwt.io(https:jwt.io). My other problem is out of the scope of Auth0 so I will accept your answer. Thanks a bunch Ryan!