I'm struggling since some weeks ago trying to interact/automate a way to upload files from a Web App created in React and upload files to a Sharepoint Online Site – in a specific folder. The WebApp is hosted in Azure and using a C# .Net Core 2.2 as backend.
I'm trying to using some kind of REST API that help me out with this task (Could be on React in frontend, or in C# Core or C# MS FW .Net for backend) I'm searching across internet a way to do it but all the testings were failed.
Someone can give me some insight, tip or advice on how to achieve this?
Use code from Microsoft WebPage (Using jQuery).
Using PnP, but on my localhost I receive a CORS problem (I'm trying using Client ID and Secret ID to interact with Sharepoint).