Hey, Here I am attaching both the requests. This is the CURL request that returns a 410 status with the 'Unregistered' error. (Timestamp: 11:07 AM IST) ~ % curl -v --header "authorization: bearer ${AUTHENTICATION_TOKEN}" --header "apns-topic: com.testcompany.sampletest" --header "apns-push-type: alert" --header "apns-priority: 10" --header "apns-expiration: 0" --data '{"aps":{"alert":{"title":"Test Notification Title","subtitle":"Test Notification Sub Title","body":"Test Notification Body"}}}' --http2 https://api.push.apple.com:443/3/device/devicetoken Host api.push.apple.com:443 was resolved. IPv6: (none) IPv4: 17.188.169.222, 17.188.169.160, 17.188.170.97, 17.188.170.156, 17.188.169.28, 17.188.169.223, 17.188.169.92, 17.188.171.221 Trying 17.188.169.222:443... Connected to api.push.apple.com (17.188.169.222) port 443 ALPN: curl offers h2,http/1.1 (304) (OUT), TLS handshake, Client hello (1): CAfile: /etc/ssl/cert.pem CApath: none (304) (IN), TLS handshake, Server hello (2): (304) (IN), TLS handshake, Unknown (8): (304) (IN), TLS handshake, Request CERT (13): (304) (IN), TLS handshake, Certificate (11): (304) (IN), TLS handshake, CERT verify (15): (304) (IN), TLS handshake, Finished (20): (304) (OUT), TLS handshake, Certificate (11): (304) (OUT), TLS handshake, Finished (20): SSL connection using TLSv1.3 / AEAD-CHACHA20-POLY1305-SHA256 / [blank] / UNDEF ALPN: server accepted h2 Server certificate: subject: C=US; ST=California; O=Apple Inc.; CN=api.push.apple.com start date: Feb 19 22:07:58 2025 GMT expire date: Mar 11 18:55:14 2026 GMT subjectAltName: host "api.push.apple.com" matched cert's "api.push.apple.com" issuer: CN=Apple Public Server RSA CA 11 - G1; O=Apple Inc.; ST=California; C=US SSL certificate verify ok. using HTTP/2 [HTTP/2] [1] OPENED stream for https://api.push.apple.com:443/3/device/devicetoken [HTTP/2] [1] [:method: POST] [HTTP/2] [1] [:scheme: https] [HTTP/2] [1] [:authority: api.push.apple.com] [HTTP/2] [1] [:path: /3/device/devicetoken] [HTTP/2] [1] [user-agent: curl/8.7.1] [HTTP/2] [1] [accept: /] [HTTP/2] [1] [authorization: bearer ${AUTHENTICATION_TOKEN}] [HTTP/2] [1] [apns-topic: com.testcompany.sampletest] [HTTP/2] [1] [apns-push-type: alert] [HTTP/2] [1] [apns-priority: 10] [HTTP/2] [1] [apns-expiration: 0] [HTTP/2] [1] [content-length: 126] [HTTP/2] [1] [content-type: application/x-www-form-urlencoded] POST /3/device/devicetoken HTTP/2 Host: api.push.apple.com User-Agent: curl/8.7.1 Accept: / authorization: bearer ${AUTHENTICATION_TOKEN} apns-topic: com.testcompany.sampletest apns-push-type: alert apns-priority: 10 apns-expiration: 0 Content-Length: 126 Content-Type: application/x-www-form-urlencoded upload completely sent off: 126 bytes < HTTP/2 410 < apns-id: FC84044A-A9F1-726D-F553-A078440B036B < Connection #0 to host api.push.apple.com left intact {"reason":"Unregistered","timestamp":1752847562639}% I have attached a screenshot of the request submitted via the UI.(Timestamp: 11:10 AM IST)