Error 400 for post user registration custom action

I would like to create a new user record in my app’s database following new user registration. I have created a custom action to achieve this. I have also added an endpoint in my app’s API for creating a new user and confirmed that the endpoint works.

However, when testing my custom action in Auth0, all I get is the following message: “Request failed with status code 400”. The action has been deployed and I have confirmed that signup works.

This is the current version of the action (please note that I will be adding metadata and security checks but for now I just want to get it working):

const axios = require("axios");

exports.onExecutePostUserRegistration = async (event) => {
   await axios.post("<API ENDPOINT>", { params: { email: event.preferred_username }});
};

The above values are based on the payload being sent by Auth0.

{
  "sub": "<SUB VALUE>",
  "nickname": "<EMAIL HANDLE>",
  "preferred_username": "<EMAIL>",
  "name": "<EMAIL>",
  "picture": "<GRAVATAR URL>",
  "updated_at": "2022-02-20T15:02:33.955Z",
  "https://www.jhipster.tech/roles": [] <--- no idea what this is
}

This is the complete Test results message:

Test Results
Error:
{
  "message": "Request failed with status code 400",
  "name": "Error"
}
Stats:
{
  "total_request_duration_ms": 385,
  "total_runtime_execution_duration_ms": 382,
  "runtime_processing_duration_ms": 8,
  "action_duration_ms": 311,
  "runtime_external_call_duration_ms": 63,
  "boot_duration_ms": 71,
  "network_duration_ms": 3
}

Any suggestions re. what I might be doing wrong and/or how I can debug this? Thanks in advance!

Figured out the problem. I was re-using the example provided in the docs and had not updated my payload object to match the expected object shape.

Wooohoo glad you have figured it out and thanks for sharing with the rest of community!