I was walking through the install instructions and hit a snag with generating tokens. I found the issue js policy. Here is a PR for what I found to be the issue, however not clear if the issue was introduced because the code committed mid-refactor.
https://github.com/apigee/microgateway-edgeauth/pull/18
In any case, the edgemicro-auth proxy will not generate tokens until this is merged. The issue can be recreated consistently following standard documentation.
https://docs.apigee.com/api-platform/microgateway/2.5.x/installing-edge-microgateway