Authentication as a Managed User using API ONLY - is it possible?

Hi all,

I have a Box account within my company's enterprise and I need to create a service which would automatically download some files shared with me. 

From what I understood, I need to use the OAuth 2 flow in order to allow the app to access the resources on my Box account's behalf. 

Now, it seemed to me the task is very simple - just provide my credentials to the service (as environment variables), receive access token and proceed with that token. 

I have been reading through Box API documentation and it actually is so confusing, I don't understand how I'd achieve what I need to get done. 

If I understand correctly, the documentation says:

- My service needs to redirect user to Box authorization URI

- Then receive the response via Redirect URI 

- Then get access token and use it to communicate with Box on my behalf

My main question is, is there a way for my service to provide Box authorization URI with credentials right away? Again, I need the process to be automated, and it seems that Box OAuth flow does not allow that to happen.

Or am I missing anything? 

Thanks.