使用Salesforce Telephony Integration API创建语音通话记录时遇URL不存在错误

正在将公司电话系统与Salesforce集成，用于在通话记录上使用Einstein Conversation Insights。已完成JWT授权且能正常调用其他Salesforce端点，但调用创建测试语音通话的接口时，收到以下404响应：

<table cellspacing=10>
    <tr>
        <td><span style="font-weight: bold; font-size: 12pt;">URL No Longer Exists</span></td>
    </tr>
    <tr>
        <td>You have attempted to reach a URL that no longer exists on salesforce.com. <br/><br/>

You may have reached this page after clicking on a direct link into the application. This direct link might be: <br/>
&#8226; A bookmark to a particular page, such as a report or view <br/>
&#8226; A link to a particular page in the Custom Links section of your Home Tab, or a Custom Link <br/>
&#8226; A link to a particular page in your email templates <br/><br/>
If you reached this page through a bookmark, you are probably trying to access something that has moved. Please update your bookmark.
            <br/>
            <br/>If you reached this page through any of the other direct links listed above, please notify your administrator to update the link.
            <br/><br/>If you reached this page through a link on our site, please <a href="/cases/logabug.jsp">report
                the broken link directly to our Support Team</a> and we will fix it promptly. Please indicate the page
            you were on when you clicked the link as well as any other related information. We apologize for the
            inconvenience.
            <br/><br/>Thank you again for your patience and assistance. And thanks for using salesforce.com!</td>
    </tr>
</table>

请求使用的POST端点为：https://myCompany.my.salesforce.com/services/telephony/v1/voiceCalls

已进行的排查步骤：

• 确认JWT授权无问题（可正常调用其他Salesforce API端点）
• 按照故障排查建议，禁用了“Enable clickjack protection for customer Visualforce pages with standard headers”选项
• 尝试过该端点及公司域名URL的多种变体，均无法解决问题

内容的提问来源于stack exchange，提问作者Sarah Weyand