How to automate the postman's grant_type='authorization_code' with newman

Question

We are trying to automate the Postman collection get API with Newman. Here, the used grant_type is authorization_code.

With Postman, it is possible to authenticate and generate the new token. The main issue which we are facing is because of the application (application setup is present in SAP BTP) login page window as SAML authentication being used.

As we have to use authorization_code as grant_type, getting login pop-up to enter the user details manually.

We want to automate the execution of this API with Newman without any manual intervention. Is there any way to perform this execution?

We have tried inside the Postman and able to generate the token. Difficulty here is, manually have to add the user login details to generate the token.