If you need or want to work with GraphQL, Strawberry is the recommended library as it has the design closest to FastAPI's design, it's all based on type annotations.
Depending on your use case, you might prefer to use a different library, but if you asked me, I would probably suggest you try Strawberry.
Here's a small preview of how you could integrate Strawberry with FastAPI:
Previous versions of Starlette included a GraphQLApp class to integrate with Graphene.
It was deprecated from Starlette, but if you have code that used it, you can easily migrate to starlette-graphene3, that covers the same use case and has an almost identical interface.
Tip
If you need GraphQL, I still would recommend you check out Strawberry, as it's based on type annotations instead of custom classes and types.