Uniform mailchimp webhook - add subscriber names

Hi,

I have set up Uniform to add subscribers to a Mailchimp list, using the example here:

https://kirby-uniform.readthedocs.io/en/latest/actions/webhook/

This is working fine, but it is only adding the email address to the list, not the first name and last name (which I am also collecting in the form as first_name and last_name).

How do I add these to the hook to get them sent through to Mailchimp? I have tried changing the names but it isn’t working. This is my hook at the moment:

webhookAction([
  'url' => 'https://us14.api.mailchimp.com/3.0/lists/{list_id}/members/',
  'json' => true,
  'params' => [
    'method' => 'POST',
    'data' => ['status' => 'subscribed'],
    'headers' => ['Authorization: Basic {api_key}'],
  ],
])

If anyone has any thoughts that would be super

Ok I worked it out. Updated code below for future travellers:

webhookAction([
  'url' => 'https://us14.api.mailchimp.com/3.0/lists/{list_id}/members/',
  'json' => true,
  'params' => [
    'method' => 'POST',
    'data' => [
      'status' => 'subscribed',
      'merge_fields' => [
        'FNAME' => $form->data('first_name'),
        'LNAME' =>  $form->data('last_name'),
      ],
     ],
     'headers' => ['Authorization: Basic {api_key}'],
  ],
])