OAuth

I am writing an app that will hypothetically integrate with OneSpan Sign. I would want the users of my app to be able to log into OneSpan Sign and grant my app permission to create Transactions in their OneSpan sign account on their behalf. Is this possible with OneSpan sign? Or would my users hypothetically need to provide my app with their OneSpan Sign API key?

On our main object, we have a quick action that fires a lightning component which on init queries for the necessary data & attachment, parses the url and then, fires an event to navigate to the url.

Recently when any user (System admin or custom profile user) clicks on the button and is redirect, the user will be sent to an remote authentication page where they must re-log to continue. This occurs twice before finally arriving at the auto prepared transaction record.