diff --git a/src/__tests__/issue-token.test.ts b/src/__tests__/issue-token.test.ts
index 3fda8f8..1b18be1 100644
--- a/src/__tests__/issue-token.test.ts
+++ b/src/__tests__/issue-token.test.ts
@@ -4,7 +4,7 @@ import mockRequests from "./lib/mock-requests";
 
 const mockRequest: ICourierAuthIssueTokenParameters = {
   scope: "user_id:example_user_id read:messages",
-  expires_in: "2 days"
+  expiresIn: "2 days"
 }
 
 const mockResponse: ICourierAuthIssueTokenResponse = {
diff --git a/src/client.ts b/src/client.ts
index c83e638..993a7b2 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -9,6 +9,7 @@ import {
   replaceBrand,
 } from "./brands";
 import { bulk } from "./bulk";
+import { postIssueToken } from "./issue-token";
 import { lists } from "./lists";
 import { notifications } from "./notifications";
 import { preferences } from "./preferences";
@@ -36,7 +37,6 @@ import {
   ICourierMessagesGetParameters,
   ICourierMessagesGetResponse,
 } from "./types";
-import { postIssueToken } from "./issue-token";
 
 const cancelMessage = (options: ICourierClientConfiguration) => {
   return async (messageId: string): Promise<ICourierMessageCancelResponse> => {
@@ -123,6 +123,7 @@ export const client = (
     getMessages: getMessages(options),
     getProfile: getProfile(options),
     getRecipientSubscriptions: getRecipientSubscriptions(options),
+    issueToken: postIssueToken(options),
     lists: lists(options),
     mergeProfile: mergeProfile(options),
     notifications: notifications(options),
@@ -134,7 +135,6 @@ export const client = (
     tenants: tenants(options),
     tokenManagement: tokenManagement(options),
     users: users(options),
-    issueToken: postIssueToken(options),
   };
 };
 
diff --git a/src/issue-token/index.ts b/src/issue-token/index.ts
index 160fe03..b2d0814 100644
--- a/src/issue-token/index.ts
+++ b/src/issue-token/index.ts
@@ -3,7 +3,10 @@ import { ICourierAuthIssueTokenParameters, ICourierAuthIssueTokenResponse } from
 
 export const postIssueToken = (options: ICourierClientConfiguration) => {
   return async (params: ICourierAuthIssueTokenParameters): Promise<ICourierAuthIssueTokenResponse> => {
-    const res = await options.httpClient.post<ICourierAuthIssueTokenResponse>(`/auth/issue-token`, params);
+    const res = await options.httpClient.post<ICourierAuthIssueTokenResponse>(`/auth/issue-token`, {
+      expires_in: params.expiresIn,
+      scope: params.scope,
+    });
     return res.data;
   };
 };
\ No newline at end of file
diff --git a/src/issue-token/types.ts b/src/issue-token/types.ts
index a4c6f41..f0a071a 100644
--- a/src/issue-token/types.ts
+++ b/src/issue-token/types.ts
@@ -1,6 +1,6 @@
 export interface ICourierAuthIssueTokenParameters {
   scope: string;
-  expires_in: string;
+  expiresIn: string;
 }
 
 export interface ICourierAuthIssueTokenResponse {
@@ -10,6 +10,6 @@ export interface ICourierAuthIssueTokenResponse {
 export interface ICourierClientAuth {
   postIssueToken: (
     scope: string,
-    expires_in?: string
+    expiresIn?: string
   ) => Promise<ICourierAuthIssueTokenResponse>;
 }