Online PHP editor | output for QKUQN

<?php $return = '{ "adm_big_picture": "", "adm_group": "", "adm_group_message": { "en": "" }, "adm_large_icon": "", "adm_small_icon": "", "adm_sound": "", "spoken_text": {}, "alexa_ssml": null, "alexa_display_title": null, "amazon_background_data": false, "android_accent_color": "FF9900FF", "android_group": "group key", "android_group_message": { "en": "group message for Android 6.0 and older" }, "android_led_color": null, "android_sound": null, "android_visibility": 1, "app_id": "3beb3078-e0f1-4629-af17-fde833b9f716", "big_picture": "https://img.onesignal.com/n/37326fcc-2baa-45da-891c-ca9454a64957.png", "buttons": null, "canceled": false, "chrome_big_picture": "", "chrome_icon": "", "chrome_web_icon": "https://picture-resource.com/icon-image.png", "chrome_web_image": "https://picture-resource.com/image.png", "chrome_web_badge": "https://picture-resource.com/badge.png", "content_available": false, "contents": { "en": "English Message" }, "converted": 1, "data": { "additional": "data", "campaign": "25" }, "delayed_option": "immediate", "delivery_time_of_day": "2:32PM", "errored": 4, "excluded_segments": [], "failed": 0, "firefox_icon": "https://picture-resource.com/firefox_icon.png", "global_image": "https://link-to-your-image.com/image-resource-file.png", "headings": { "en": "English Message Title 😊" }, "id": "fd1723c6-bfaf-4f53-b4f4-0408ff43e18a", "include_player_ids": null, "include_external_user_ids": null, "included_segments": [ "Subscribed Users" ], "thread_id": null, "ios_badgeCount": 1, "ios_badgeType": "Increase", "ios_category": "", "ios_sound": "explosion.wav", "apns_alert": {}, "isAdm": false, "isAndroid": true, "isChrome": false, "isChromeWeb": true, "isAlexa": false, "isFirefox": true, "isIos": true, "isSafari": true, "isWP": false, "isWP_WNS": false, "isEdge": true, "large_icon": "https://img.onesignal.com/n/b5cadcf0-1297-4489-b865-545b421d8c5d.png", "priority": 5, "queued_at": 1580510246, "remaining": 0, "send_after": 1580510246, "completed_at": 1580510247, "small_icon": "small_icon", "successful": 232, "received": 5, "tags": null, "filters": null, "template_id": null, "ttl": 777, "url": "https://onesignal.com/blog", "web_url": null, "app_url": null, "web_buttons": null, "web_push_topic": null, "wp_sound": "", "wp_wns_sound": "", "platform_delivery_stats": { "edge_web_push": { "successful": 2, "failed": 0, "errored": 0 }, "chrome_web_push": { "successful": 26, "failed": 0, "errored": 0 }, "firefox_web_push": { "successful": 1, "failed": 0, "errored": 0 }, "android": { "successful": 198, "errored": 1, "failed": 0 }, "safari_web_push": { "successful": 3, "failed": 0, "errored": 0 }, "ios": { "successful": 2, "errored": 3, "failed": 0 } }, "ios_attachments": { "id": "https://img.onesignal.com/n/23f60ba6-8f2e-4ce1-bdf5-86e6286c2e39.png" } }'; $yummy = json_decode($return, true); echo "checking---".$yummy['app_id'];