Consumer API - Using Authentication Framework via a "background" service

Question

I'm working on an API project that will use Banno's Consumer API to gather Account/Transaction data as part of a "background" service to sync with a Partner's system. By background service I mean that the User is not present. The Partner will send over identifiers for the given User and this API being developed would retrieve this data and send it back to the Partner for them to perform the sync with their data.

In conjunction with this background API, I have implemented a Plugin so I know that with Banno's Authentication Framework a User has to have a valid session to receive a token via its 0auth process to consume the Consumer API. My question is, is there some mechanism or alternative approach with the Consumer API that would allow for a User to be authenticated (without signing into their Banno account via username/password) that would allow a background service type of manner to interact with the Consumer API?

The API project I'm working on is accessed via an API the Partner has implemented. This "sync" process for Accounts/Transactions can be triggered after a User has logged into their system (which happens when the User signs into their Banno account) but it can also be triggered on a scheduled basis all of which the User is not present to authenticate themselves in Banno. Additionally, since this API is necessarily invoked in conjunction with the User accessing Banno I would not be able to "share" the access token across the line.

The Authentication Framework and Consumer API Framework docs don't seem to point out anything along the lines of what I'm looking for in order to achieve this background service type of operation so I'm not sure if this 1) possible 2) if possible, how to go about implementing this.