# Sign in or send an API key

> authentication-required: HTTP 401. Send Authorization: Bearer with an mdh_ API key. Sign-in through https://mydatahub.emailmovers.com/id is planned.

Source: https://emailmovers.com/mydatahub/docs/errors/authentication-required

`authentication-required` is returned with HTTP status 401. Its type URI is `https://emailmovers.com/mydatahub/docs/errors/authentication-required`.

## What it means

The operation needs a credential and none was sent, or the one sent is not valid. The response carries a WWW-Authenticate challenge asking for three read scopes.

## What to do

Send Authorization: Bearer with an mdh_ API key. Sign-in through https://mydatahub.emailmovers.com/id is planned.

## Example

```json
{
  "type": "https://emailmovers.com/mydatahub/docs/errors/authentication-required",
  "title": "Sign in or send an API key",
  "status": 401,
  "code": "authentication-required",
  "detail": "Send an API key as Authorization: Bearer.",
  "next_step": "Send Authorization: Bearer with an mdh_ API key. Sign-in through https://mydatahub.emailmovers.com/id is planned."
}
```

## See also

- [Authentication](https://emailmovers.com/mydatahub/docs/authentication.md)

All problem types are listed on [Errors](https://emailmovers.com/mydatahub/docs/errors.md).