I would recommend to give EventGrid a shot.

There is a quite good example on the docs already explaining exactly your case https://learn.microsoft.com/en-us/azure/azure-functions/functions-event-grid-blob-trigger?pivots=programming-language-csharp

Create an Event Subscription for the Blob Created event and then create a new EventGridTrigger Function.

Event based trigger are btw the recommended way for blob storage, as it has lower latency and calls on the storage account