License

The license key field allows you to check a license key and display the status of the license.

'licenseKey'         => [
    'type'        => 'license',
    'panel'       => 'license',
    'label'       => esc_html__( 'License Key', 'blockify-pro' ),
    'description' => $license_message,
    'default'     => [
        'license'       => $license_key,
        'licenseStatus' => $license_status,
    ],
    'endpoint'    => 'fieldify/v1/license?key={license_key}',
    'permission'  => 'administrator',
],

The license field checks the license key against an endpoint. The licen_key tag is replaced with the license key entered by the user:

add_action( 'rest_api_init', __NAMESPACE__ . '\\register_license_rest_route' );
/**
 * Registers the license REST route.
 *
 * @since 0.0.2
 *
 * @return void
 */
function register_license_rest_route(): void {
  register_rest_route(
    'fieldify/v1',
    '/license',
    [
      'methods'             => WP_REST_Server::READABLE,
      'callback'            => __NAMESPACE__ . '\\validate_license',
      'permission_callback' => static fn(): bool => current_user_can( 'manage_options' ),
      'args'                => [
        'key' => [
          'required' => true,
        ],
      ],
    ]
  );
}

/**
 * Validates the license key.
 *
 * @since 0.0.2
 *
 * @return array
 */
function validate_license(): array {
  $key = filter_input( INPUT_GET, 'key', FILTER_SANITIZE_FULL_SPECIAL_CHARS );

  if ( $key === '123') {
      $status  = 'valid';
        $message = 'License key is valid.';
    } else {
        $status  = 'invalid';
        $message = 'License key is invalid.';
  }

  return [
    'license' => $status,
    'message' => $message,
  ];
}