Why does my delay job got undefined variable?

I have been pulling my hair for hours, hopefully someone could help me with this problem. I have a job that got dispatch from controller. My job working as expected when I use code below:

SendToSlack::dispatch($get_order_details, $transaction_id, $customerDet->ord_shipping_cus_name)->onConnection('sync');

But it get undefined variable error when I put 60 seconds delay on it

SendToSlack::dispatch($get_order_details, $transaction_id, $customerDet->ord_shipping_cus_name)->delay(Carbon::now()->addSeconds(60));

I'm pretty sure this error caused by the delay, tried some googling but no luck finding solution.

Thanks in advance.

via Chebli Mohamed