rest – How do you download the actual HTML content of a SharePoint Online page using OAuth credentials (Bearer token)?

How do you download the actual HTML content of a SharePoint Online page using OAuth credentials (Bearer token)?

I want to download the HTML content from here: https://mytenant.sharepoint.com/sites/theSiteHere/

You can download the HTML of this page when using FedAuth/rtFa or SPOIDCRL cookies (SAML user account authentication), but you get a 401 Unauthorized if you try to HTTP Get this URL using a bearer token.

To download files from sharepoint using a bearer token, you must make requests like this:

https://mytenant.sharepoint.com/sites/theSiteHere/_api/Web/getfilebyserverrelativeurl('/sites/theSiteHere/SitePages/Home.aspx')/$value

The results in garbage asp.net code that does not have my HTML content.

<%@ Assembly Name="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"%> <%@ Page Language="C#" Inherits="Microsoft.SharePoint.WebControls.ClientSidePage"       %> <%@ Import Namespace="Microsoft.SharePoint" %> <%@ Register Tagprefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Register Tagprefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %> <%@ Import Namespace="Microsoft.SharePoint" %> <%@ Assembly Name="Microsoft.Web.CommandUI, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<html xmlns:mso="urn:schemas-microsoft-com:office:office" xmlns:msdt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882"><head>
<!--(if gte mso 9)><SharePoint:CTFieldRefs runat=server Prefix="mso:" FieldList="FileLeafRef,ClientSideApplicationId,PageLayoutType,CanvasContent1,BannerImageUrl,BannerImageOffset,PromotedState,FirstPublishedDate,LayoutWebpartsContent,_TopicHeader,_SPSitePageFlags,_SPAssetFolderId"><xml>
<mso:CustomDocumentProperties>
<mso:PageLayoutType msdt:dt="string">Home</mso:PageLayoutType>
<mso:ClientSideApplicationId msdt:dt="string">B6917CB1-93A0-4B97-A84D-7CF49975D4EC</mso:ClientSideApplicationId>
<mso:ContentTypeId msdt:dt="string">0x0101009D1CB255DA76424F860D91F20E6C4118</mso:ContentTypeId>
</mso:CustomDocumentProperties>
</xml></SharePoint:CTFieldRefs><!(endif)-->
<title>Home</title></head>

What is the correct way to actually download the combined HTML content of this page using a bearer token?