Authenticating application with other realm's JWT

Hello -
I have 2 separate OIDC keycloak instances representing corporate user realm and second for a specific platform realm. What I want is once end user is logged in to the corporate realm using mobile app, the app would call the platform API service with authenticated JWT from login and API should be able to link and import that identity into platform realm.
I can setup platform realm as an identity broker to authenticate using corporate realm but that needs user/browser login. Is there way to import corp realm user into platform user without going through user interaction?