Supplementary note, the following shell is executed to send the message DEVICE_TOKEN=xxxxx APNS_HOST_NAME=api.sandbox.push.apple.com TEAM_ID=team_id TOKEN_KEY_FILE_NAME=file_name.p9 AUTH_KEY_ID=id TOPIC=widget_topic JWT_ISSUE_TIME=$(date +%s) JWT_HEADER=$(printf '{ "alg": "ES256", "kid": "%s" }' "${AUTH_KEY_ID}" | openssl base64 -e -A | tr -- '+/' '-_' | tr -d =) JWT_CLAIMS=$(printf '{ "iss": "%s", "iat": %d }' "${TEAM_ID}" "${JWT_ISSUE_TIME}" | openssl base64 -e -A | tr -- '+/' '-_' | tr -d =) JWT_HEADER_CLAIMS="${JWT_HEADER}.${JWT_CLAIMS}" JWT_SIGNED_HEADER_CLAIMS=$(printf "${JWT_HEADER_CLAIMS}" | openssl dgst -binary -sha256 -sign "${TOKEN_KEY_FILE_NAME}" | openssl base64 -e -A | tr -- '+/' '-_' | tr -d =) AUTHENTICATION_TOKEN="${JWT_HEADER}.${JWT_CLAIMS}.${JWT_SIGNED_HEADER_CLAIMS}" curl -v \ --header "apns-topic: $TOPIC" \ --header "apns-push-type: widgets" \ --header "authorization: bearer $AUTHENTICATION_TOKEN" \ --data '{"aps":{"content-changed": true}}' \ --http2 https://${APNS_HOST_NAME}/3/device/${DEVICE_TOKEN}