Template app on AppSource - SSO authentication interface

[DesNaidoo]

Hi Guys

I hope I dont sound loke a noob.😁

I am busy documenting a process for my company to implement an app on appsource. We want to do something similar to the Xero app available on appsource. When using the Xero app, it allows you to connect to your own data. When you click on connect, a xero "web" login screen appears where the user can enter his credentials to grab his own Xero data.

So my question is, how is that part implemented? 

once you click on connect...

I would like to know how to implement a login like this (oAuth AWS cognito in our case) and have it grab user centric data from secure Snowflake views. Would we need to create a custom connector to achieve this or an API? I need to document the implementation process for business and the developers.

Thanks in advance...cheers