Identity API is not supported for this add-in

Question

We are creating an add-in that needs to retrieve the user's M365 email - the add-in is a taskpane and made for Word and Excel. The issue occurs when getting the access token prior to calling the graph api.

Office.onReady(async () => {
  try {
	// fails here
    const accessToken = await OfficeRuntime.auth.getAccessToken({ allowSignInPrompt: true });

    const user = await getUserDetails(accessToken);
    document.getElementById("userInfo").innerText = 
      `Name: ${user.displayName}\nEmail: ${user.mail || user.userPrincipalName}`;
  	} 
  catch (error) {   
	console.error("Error:", error);
  }
});

The error is:

{name: 'API Not Supported', message: 'The identity API is not supported for this add-in.', code: 13000}

The add-in manifest is:

<?xml version="1.0" encoding="UTF-8"?>
<OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0"
           xmlns:ov="http://schemas.microsoft.com/office/taskpaneappversionoverrides"
           xsi:type="TaskPaneApp">

  <Id>AABBCCDD-AAAA-2222-1111-999999111111</Id>
  <Version>1.0.0.0</Version>
  <ProviderName>Contoso7</ProviderName>
  <DefaultLocale>en-US</DefaultLocale>
  <DisplayName DefaultValue="Edstest2228"/>
  <Description DefaultValue="Fetch and display user name/email from Microsoft Graph."/>
  <IconUrl DefaultValue="https://localhost/Icons/AddInTaskpane_Button_Icon.png"/>
  <SupportUrl DefaultValue="https://localhost"/>

  <Hosts>
    <Host Name="Document" />
  </Hosts>

  <Requirements>
    <Sets DefaultMinVersion="1.1">
      <Set Name="SharedRuntime"/>
    </Sets>
  </Requirements>

  <DefaultSettings>
    <SourceLocation DefaultValue="https://localhost/simple.html"/>
  </DefaultSettings>

  <Permissions>ReadWriteDocument</Permissions>

  <VersionOverrides Version="1.0">
    <Hosts>
      <Host xsi:type="Word">
        <DesktopFormFactor>
          <FunctionFile resid="taskpaneUrl"/>
          <ExtensionPoint xsi:type="PrimaryCommandSurface">
            <CustomTab id="Tab1">
              <Group id="Group1">
                <Label resid="groupLabel"/>
                <Control xsi:type="Button" id="ShowTaskpane">
                  <Label resid="buttonLabel"/>
                  <Supertip>
                    <Title resid="buttonTitle"/>
                    <Description resid="buttonDesc"/>
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="icon16"/>
                    <bt:Image size="32" resid="icon32"/>
                    <bt:Image size="80" resid="icon80"/>
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="taskpaneUrl"/>
                  </Action>
                </Control>
              </Group>
            </CustomTab>
          </ExtensionPoint>
        </DesktopFormFactor>
      </Host>
    </Hosts>
    <Resources>
      <bt:Images>
        <bt:Image id="icon16" DefaultValue="https://localhost/Icons/AddInTaskpane_Button_Icon.png"/>
        <bt:Image id="icon32" DefaultValue="https://localhost/Icons/AddInTaskpane_Button_Icon.png"/>
        <bt:Image id="icon80" DefaultValue="https://localhost/Icons/AddInTaskpane_Button_Icon.png"/>
      </bt:Images>
      <bt:Urls>
        <bt:Url id="taskpaneUrl" DefaultValue="https://localhost/simple.html"/>
      </bt:Urls>
      <bt:ShortStrings>
        <bt:String id="groupLabel" DefaultValue="User Info2"/>
        <bt:String id="buttonLabel" DefaultValue="Get User Info"/>
        <bt:String id="buttonTitle" DefaultValue="Get Info2"/>
        <bt:String id="buttonDesc" DefaultValue="Get the signed-in user's name and email."/>
      </bt:ShortStrings>
    </Resources>	
	<WebApplicationInfo>
		<Id>19ff57b6-a68d-46fe-8358-77c42064a174</Id>
		<Resource>https://graph.microsoft.com</Resource>
		<Scopes>
			<Scope>openid</Scope>
			<Scope>profile</Scope>
			<Scope>email</Scope>
			<Scope>User.Read</Scope>
		</Scopes>	
	</WebApplicationInfo>
  </VersionOverrides>
</OfficeApp>

The html and javascript for the add-in is hosted locally:

https://localhost/simple.html

Here are the details for the Azure application: