slim framework firebase push notification

I’m using the Slim framework as a PHP API and I’m sending Firebase push notifications on my website. The problem is that when I try to add data to the notification, I receive two notifications for a single send. Can you help me, please?

I’m using the Slim framework as a PHP API and I’m sending Firebase push notifications on my website. The problem is that when I try to add data to the notification, I receive two notifications for a single send.