By name it is clear that we will have to include an app that makes a seller part for this online shopping platform.
We can create a separate seller app where there are full details of the seller and their credentials along with a dashboard showing the items sold by them and orders they received.
We can make two separate apps and integrate the data flow between them by using django-REST framework.
So main aim is to use this framework and make an app named seller which includes a flow of items data between them.
Although this is a big task, But better to discuss here if not understood, and a minor support is also appreciated.
You can support by creating models and structure of app and many more.
Thanks.

The functionality of password reset is not ye completed since the app is not able to send email to the user to allow them to reset their password.
So the requirement is that we have to implement the email method in django which can send email as and when needed.