I need to create a React app that gives the possibility of uploading files on Dropbox, and I'm having some doubts about how to make the Dropbox Authentication with Javascript code. I don't want the user to be redirected to the "Authorization page" where he has to click on some button, but I want to get the permission to my App and my files only by code. I tried to use the official SDK but I got redirected to said authorization page. Is there a way to do that, with or without the official SDK? Or am I thinking it wrong and the authorization page actually appears just one time and the next ones I can get the authorization and the token just with my Javascript code?