Multi database support in prisma

I have 3 databases in my project. Every database has different data. But they have some relation between them. For example on the transaction database in my transaction, it has a userId stored and in the Default database User table has this user.

Now how to manage these multi-database and cross-relation between databases in Prisma?

I want to have the possiblity to keep relation betwwen my different databases in prisma