delegation

Below are the step we use for hand drawn signature capture using api

I have code that follows which I have used to setup delegation for various users.  All of the sudden users no longer have delegated access and using the code reports it setup delegation but it doesn't work.  We have a main account where users are created, they are assigned rights in a subaccount and in that subaccount is the "user" where I setup delegation.  Has the API call changed at all?

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?