fastapi: Usage Graphene Subscriptions in FastAPI - Usage of Starlette-Graphene3 failed

I wanted to make the subscriptions of graphene work in FastAPI. Unfortuantely I saw two other repositories who asked a similar thing and no conclusion made there. After some research I found the package starlette-graphene3, which makes uploading files and the subscription possible in Starlette. Due to the usage of the the GraphQLApp-class of starlette i thought, that this is going to work. Unfortunately there is a little problem when using starlette-graphene3 with fastapi:

• When installing starlette-graphene3 I get the error: ERROR: fastapi 0.63.0 has requirement starlette==0.13.6, but you'll have starlette 0.14.1 which is incompatible., which makes FastAPI not work anymore.

My questions are:

• is it in planning to use a newer Starlette version, that starlette-graphene3 could be used
• Any other way to make subscriptions work in FastAPI?

When trying to use GraphQL like in the documentation of FastAPI with subscriptions i get the error: "Subscriptions are not allowed. You will need to either use the subscribe function or pass allow_subscriptions=True"

Code to reproduce:

from fastapi import FastAPI
from starlette.graphql import GraphQLApp
import graphene
import asyncio

class Subscription(graphene.ObjectType):
    count = graphene.Int(upto=graphene.Int())

    async def subscribe_count(root, info, upto=3):
        for i in range(upto):
            yield i
            await asyncio.sleep(1)


app = FastAPI()
app.add_route("/graphql", GraphQLApp(schema=graphene.Schema(subscription=Subscription)))