Choosing the authentification method

Welcome to Box! Thanks so much for using our platform and development forum. 

Are you using our python SDK? 

Best, 

Yes, I actually tried the example (auth.py), but it's launching a localhost server, etc. Can't make it work.

I also followed the following lines : https://github.com/box/box-python-sdk#id4
But I don't understand why you need to create an user and how can you use an already created user ?
Everytime I'm trying a request on any file, I've a 404 error.

 Thanks for the info! Let's go back to your original message so I can get some more context. 

"The developer token is working but limited to one hour and the transfer might be longer. I'm facing difficulties to program a refresh token program."

Just in case you don't know, the developer token will be a token associated with the Box account logged into the developer console when you generate this token. Therefore, if you're logged in as xyz@box.com, you can only interact with content xyz@box.com has access to. 

"I used the OAuth2 JWT, but I can't use the client object created, I can only create user with it. Therefore, after creating a user to the app, and manually giving the right to access different folders, etc. How can I use this created user to upload my files ?"

Did you make an app user? You want to upload the content as the app user, correct? 

Yes, with the dev token it's working but it's limited to 1h. Yes, I made an app user and I gave access to the right folders to allow him to upload but how can I get the user created in the code ? Because I can only find how to create this user, not how to use it therefore.