Can we use same tenant in Auth0 for custom login and login with SSO using auth0?

We have a platform that supports 2 user types say, retailer and vendor.

Existing user type is retailer and it is working fine with Auth0 custom login.

We need to bring in another user type vendor with different home page and other pages. Vendor also supports SSO login.Heard from Auth0 that, incase if you want to allow SSO through Auth0, we must be using Universal login flow in Auth0. Since our one existing user type is using a custom flow, how can we integrate the authentication flow for both user types to one tenant?