Pass the user's context to OKTA Authentication for getting token for OData API

We are starting using OKTA Auth for OData API's and what I have got is we have to pass user's information (domain email and password) to generate token and then we can use that token to call APIs. But we cannot pass each user's information to create token, so eventually, we have to pass a service account to get a token. The problem is we don't want to use Service Account as that will reflect the same account in our Mod Logs. We want to get a token for OData with the user's context (like some sort of using SSO). Does anybody have any idea on how to achieve this? that would be really helpful!