Pass Checkbox Value Field

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1

My developer is MIA so I am trying to resolve this issue. I have a checkbox for SMSopt-in, field 12, on my form. I need that set to true when it is checked so it can be passed on. What needs to be added?

See below.

$body = array(
		'EmailAddress'         => rgar( $entry, '3' ),
		'SiteGUID'             => PROMOLYTICS_FQS_SITE_GUID,
		'ListID'               => PROMOLYTICS_FQS_LIST_ID,
		'_theme'               => PROMOLYTICS_FQS_THEME_ID,
		'SuppressConfirmation' => false,
		'Action'               => 'Subscribe',
		'FirstName'            => rgar( $entry, '2.1' ),
		'LastName'             => rgar( $entry, '2.2' ),
		'Phone'                => rgar( $entry, '4' ),
		'Sweepstakes2019' 		 => rgar( $entry, '1' ),
		'Sweepstakes2019State' => rgar( $entry, '5' ),
		'Zip'                  => rgar( $entry, '5' ),
		'StoreCode'            => rgar( $entry, '6' ),
		'SMSOptin'             => rgar( $entry, '12' ),
2

The logic for that is mentioned in this topic: