using jwt_auth_token_before_sign creates invalid json

[simonh1000]

Issue Name

Prerequisites

Please answer the following questions for yourself before submitting an issue.

• [x] I am running the latest plugin version
• [x] I am running the latest WordPress version
• [ ] I know what PHP version I'm using
• [x] I checked the documentation and found no answer
• [x] I checked to make sure that this issue has not already been filed

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

• WordPress version 6.x
• PHP Version
• 1.3.4

Expected Behavior

I'm not a PHP specialist, so i'm just trying to extend code I fond on stackoverflow

I have

add_action( 'jwt_auth_token_before_sign', 'jwt_token', 10, 2 );

function jwt_token($token, $user) {
  $data = [
    'user' => [
        'id' => $user->data->ID,
        'name' => $user->data->display_name,
        'roles' => implode(',', $user->roles)
    ]
  ];
  $token['data'] = $data;
  return $token;
}

the trouble is that when this returns after an auth request I get

Array{
    "token": "eyJ0e...NcbMJcQ",
    "user_email": "...@gmail.com",
    "user_nicename": "xyz",
    "user_display_name": "xyz"
}

the word Array is then messing up the parsing in the client

Any ideas how to return a $token that continues to json encode properly?