I have the following implementation in JS/Node for interacting with App Store server, yet all responses are 401 Unauthorized: % curl -v -H 'Authorization: Bearer XXX' "https://api.storekit-sandbox.itunes.apple.com/inApps/v1/subscriptions/4" * Trying 17.56.138.10... * TCP_NODELAY set * Connected to api.storekit-sandbox.itunes.apple.com (17.56.138.10) port 443 (#0) * ALPN, offering h2 * ALPN, offering http/1.1 * successfully set certificate verify locations: *  CAfile: /etc/ssl/cert.pem  CApath: none * TLSv1.2 (OUT), TLS handshake, Client hello (1): * TLSv1.2 (IN), TLS handshake, Server hello (2): * TLSv1.2 (IN), TLS handshake, Certificate (11): * TLSv1.2 (IN), TLS handshake, Server key exchange (12): * TLSv1.2 (IN), TLS handshake, Server finished (14): * TLSv1.2 (OUT), TLS handshake, Client key exchange (16): * TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1): * TLSv1.2 (OUT), TLS handshake, Finished (20): * TLSv1.2 (IN), TLS change cipher, Change cipher spec (1): * TLSv1.2 (IN), TLS handshake, Finished (20): * SSL connection using TLSv1.2 / ECDHE-RSA-CHACHA20-POLY1305 * ALPN, server accepted to use h2 * Server certificate: * subject: businessCategory=Private Organization; jurisdictionCountryName=US; jurisdictionStateOrProvinceName=California; serialNumber=C0806592; C=US; ST=California; L=Cupertino; O=Apple Inc.; OU=management:idms.group.506364; CN=commercegateway.itunes.apple.com * start date: Jun 4 18:57:38 2021 GMT * expire date: Jul 4 18:57:37 2022 GMT * subjectAltName: host "api.storekit-sandbox.itunes.apple.com" matched cert's "api.storekit-sandbox.itunes.apple.com" * issuer: C=US; O=Apple Inc.; CN=Apple Public EV Server RSA CA 2 - G1 * SSL certificate verify ok. * Using HTTP2, server supports multi-use * Connection state changed (HTTP/2 confirmed) * Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0 * Using Stream ID: 1 (easy handle 0x7fca1e00d600) > GET /inApps/v1/subscriptions/4 HTTP/2 > Host: api.storekit-sandbox.itunes.apple.com > User-Agent: curl/7.64.1 > Accept: */* > Authorization: Bearer XXX >  * Connection state changed (MAX_CONCURRENT_STREAMS == 1024)! < HTTP/2 401  < server: daiquiri/3.0.0 < date: Thu, 26 Aug 2021 02:57:57 GMT < content-type: text/plain < strict-transport-security: max-age=31536000; includeSubDomains < x-apple-jingle-correlation-key: KPN55ROQH3BLNL2AG7S7NEFZHA < x-daiquiri-instance: daiquiri:17578001:mr85p00it-hyhk04164801:7987:21RELEASE140:daiquiri-amp-commerce-clients-ext-002-mr <  Unauthenticated Request ID: KPN55ROQH3BLNL2AG7S7NEFZHA.0.0 * Connection #0 to host api.storekit-sandbox.itunes.apple.com left intact * Closing connection 0 The header is hashed with ES256 as follows: function jwtHeader() { let d = new Date() d.setHours(d.getHours() + 1) return { "iss": issuerID, "iat": Math.floor(new Date().getTime()/1000), "exp": Math.floor(d.getTime()/1000), "aud": "appstoreconnect-v1", "nonce": Utils.uuid(), "bid": bundleID } } function headerHash(cb) { fs.readFile(appleKeys.p8, 'utf-8', function(err, key) { if (err) return cb(err) let headers = jwtHeader() console.log(headers) jwt.sign(headers, key, { algorithm: 'ES256' }, cb) }) } My In-App Purchase Key ID is completely unused. Besides registering a callback for notifications, I can't find anywhere to register my URL. In short, I can't tell what's not configured or carried out improperly on my end.