Connecting an existing graphQL endpoint to studio

Taking this tutorial and trying to connect the graphQL endpoint to my studio account.

However the only way to publish a subgraph to a super graph is through rover.
what is the argument that I should pass for schema in the command line if I do not want to deploy the app locally (see the command below). or how do I connect a remote graphQL endpoint to a blanket supergraph?

rover subgraph publish Observability-Demo-x8oh8n@current
–schema ./schema.graphql
–name recipes