You need to deploy two Azure virtual machines to two Azure regions, but also create a Traffic Manager profile.

Reference:
https://docs.microsoft.com/en-us/azure/storage/common/storage-account-overview
https://docs.microsoft.com/en-us/azure/storage/common/storage-redundancy?toc=/azure/storage/blobs/toc.json

Compared to HTTP, AMQP is easy to scale.
Note: Facts pro-AMQP
Delivering messages with AMQP gives you reliability and being asynchronous allows you to not worry about the delivery at all.
Reference:
https://dev.to/fedejsoren/amqp-vs-http

Explanation

Box 1: Install a self-hosted integration runtime
The Integration Runtime is a customer-managed data integration infrastructure used by Azure Data Factory to provide data integration capabilities across different network environments.
Box 2: Create a pipeline
With ADF, existing data processing services can be composed into data pipelines that are highly available and managed in the cloud. These data pipelines can be scheduled to ingest, prepare, transform, analyze, and publish data, and ADF manages and orchestrates the complex data and processing dependencies References:
https://docs.microsoft.com/en-us/azure/machine-learning/team-data-science-process/move-sql-azure-adf

Explanation

Box 1: Web applications
The Authorization Code Grant Type is used by both web apps and native apps to get an access token after a user authorizes an app.
Note: The Authorization Code grant type is used by confidential and public clients to exchange an authorization code for an access token.
After the user returns to the client via the redirect URL, the application will get the authorization code from the URL and use it to request an access token.
Answers:
Not Headless device authentication:
A headless system is a computer that operates without a monitor, graphical user interface (GUI) or peripheral devices, such as keyboard and mouse.
Headless computers are usually embedded systems in various devices or servers in multi-server data center environments. Industrial machines, automobiles, medical equipment, cameras, household appliances, airplanes, vending machines and toys are among the myriad possible hosts of embedded systems.
Box 2: Client Credentials
How to include additional client data
In case you need to store additional details about a client that don't fit into the standard parameter set the custom data parameter comes to help:
POST /c2id/clients HTTP/1.1
Host: demo.c2id.com
Content-Type: application/json
Authorization: Bearer ztucZS1ZyFKgh0tUEruUtiSTXhnexmd6
{
"redirect_uris" : [ "https://myapp.example.com/callback" ],
"data" : { "reg_type" : "3rd-party",
"approved" : true,
"author_id" : 792440 }
}
The data parameter permits arbitrary content packaged in a JSON object. To set it you will need the master registration token or a one-time access token with a client-reg:data scope.
Reference:
https://developer.okta.com/blog/2018/04/10/oauth-authorization-code-grant-type
https://connect2id.com/products/server/docs/guides/client-registration