@BeUnique Thank you for reaching out.
Since you have the .Net code already to download the documents using a REST API, you should move the code to an Azure Function App or Azure API Service.
Here are a couple of tutorials to help you get started.
https://learn.microsoft.com/en-in/azure/app-service/app-service-web-tutorial-rest-api
https://learn.microsoft.com/en-in/azure/azure-functions/create-first-function-vs-code-csharp?tabs=in-process&pivots=programming-runtime-functions-v4
For storing the documents, you could use Azure blob storage
Here is a tutorial
https://learn.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-dotnet
Please let us know if you have any further questions.
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