diff --git a/README.md b/README.md
index b3578f6b..eab47efe 100644
--- a/README.md
+++ b/README.md
@@ -28,9 +28,9 @@ npm i -s @scaleleap/selling-partner-api-sdk
 
 A few things to get started:
 
-- [Registering as a developer](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/developer-guide/SellingPartnerApiDeveloperGuide.md#registering-as-a-developer)
-- [Registering your Selling Partner API application](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/developer-guide/SellingPartnerApiDeveloperGuide.md#registering-your-selling-partner-api-application)
-- [Authorizing Selling Partner API applications](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/developer-guide/SellingPartnerApiDeveloperGuide.md#authorizing-selling-partner-api-applications)
+- [Registering as a developer](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/developer-guide/SellingPartnerApiDeveloperGuide.md#registering-as-a-developer)
+- [Registering your Hybrid Selling Partner API applications](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/developer-guide/SellingPartnerApiDeveloperGuide.md#hybrid-selling-partner-api-applications)
+- [Authorizing Selling Partner API applications](https://github.com/amzn/selling-partner-api-docs/blob/main/guides/en-US/developer-guide/SellingPartnerApiDeveloperGuide.md#authorizing-selling-partner-api-applications)
 
 ### Basic Usage
 
diff --git a/package-lock.json b/package-lock.json
index 8850c47a..caa84f32 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2925,6 +2925,15 @@
         "uuid": "8.3.2"
       },
       "dependencies": {
+        "axios": {
+          "version": "0.21.4",
+          "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
+          "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+          "dev": true,
+          "requires": {
+            "follow-redirects": "^1.14.0"
+          }
+        },
         "tslib": {
           "version": "2.3.1",
           "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.3.1.tgz",
@@ -4659,11 +4668,11 @@
       }
     },
     "axios": {
-      "version": "0.21.4",
-      "resolved": "https://registry.npmjs.org/axios/-/axios-0.21.4.tgz",
-      "integrity": "sha512-ut5vewkiu8jjGBdqpM44XxjuCjq9LAKeHVmoVfHVzy8eHgxxq8SbAVQNovDA8mVi05kP0Ea/n/UzcSHcTJQfNg==",
+      "version": "0.24.0",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-0.24.0.tgz",
+      "integrity": "sha512-Q6cWsys88HoPgAaFAVUb0WpPk0O8iTeisR9IMqy9G8AbO4NlpVknrnQS03zzF9PGAWgO3cgletO3VjV/P7VztA==",
       "requires": {
-        "follow-redirects": "^1.14.0"
+        "follow-redirects": "^1.14.4"
       }
     },
     "babel-jest": {
@@ -8215,9 +8224,9 @@
       "dev": true
     },
     "follow-redirects": {
-      "version": "1.14.3",
-      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.14.3.tgz",
-      "integrity": "sha512-3MkHxknWMUtb23apkgz/83fDoe+y+qr0TdgacGIA7bew+QLBo3vdgEN2xEsuXNivpFy4CyDhBBZnNZOtalmenw=="
+      "version": "1.14.4",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.14.4.tgz",
+      "integrity": "sha512-zwGkiSXC1MUJG/qmeIFH2HBJx9u0V46QGUe3YR1fXG8bXQxq7fLj0RjLZQ5nubr9qNJUZrH+xUcwXEoXNpfS+g=="
     },
     "for-in": {
       "version": "1.0.2",
diff --git a/package.json b/package.json
index 383e23a4..dcce4877 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
   "types": "lib/index.d.ts",
   "dependencies": {
     "aws4-axios": "2.4.3",
-    "axios": "0.21.4",
+    "axios": "0.24.0",
     "http-status-codes": "2.1.4",
     "ts-error": "1.0.6"
   },
diff --git a/src/helpers/api-client-helpers.ts b/src/helpers/api-client-helpers.ts
index 702632a2..3484916a 100644
--- a/src/helpers/api-client-helpers.ts
+++ b/src/helpers/api-client-helpers.ts
@@ -40,7 +40,7 @@ export class ApiClientHelpers {
       axiosInstance = globalAxios.create({
         headers: {
           'user-agent': USER_AGENT,
-          'x-amz-access-token': accessToken,
+          'x-amz-access-token': accessToken ?? '',
         },
       })
 
diff --git a/src/types/errors/selling-partner-api-errors.ts b/src/types/errors/selling-partner-api-errors.ts
index 729becf2..43423824 100644
--- a/src/types/errors/selling-partner-api-errors.ts
+++ b/src/types/errors/selling-partner-api-errors.ts
@@ -1,4 +1,5 @@
 /* eslint-disable max-classes-per-file */
+import { AxiosResponseHeaders } from 'axios'
 import { ExtendableError } from 'ts-error'
 
 export interface ModelErrorContainer {
@@ -35,7 +36,7 @@ export class SellingPartnerGenericError extends ExtendableError {
 
   public requestId: string
 
-  public constructor(error: ModelError, headers: Headers) {
+  public constructor(error: ModelError, headers: AxiosResponseHeaders) {
     super(error.details)
 
     this.code = error.code
@@ -53,7 +54,7 @@ export class SellingPartnerUnsupportedMediaTypeError extends SellingPartnerGener
 export class SellingPartnerTooManyRequestsError extends SellingPartnerGenericError {
   public rateLimit?: number
 
-  public constructor(error: ModelError, headers: Headers) {
+  public constructor(error: ModelError, headers: AxiosResponseHeaders) {
     super(error, headers)
     this.rateLimit =
       Number(headers['x-amzn-RateLimit-Limit']) ||