How to use proxy?

[IceBlizz6]

I'm trying to use a proxy.
But my requests are still being sent to sanity.io

import sanityClient from "@sanity/client"

const config = {
	projectId: "aaaa",
	dataset: "production",
	useCdn: false,
	apiVersion: "2021-08-31",
	proxy: "http://localhost:8080/sanity",
}

const client = sanityClient(config)
client.fetch("...")

Requests are sent to https://aaaa.api.sanity.io/....
It seems like the proxy is being ignored.

How do i make sanity client send requests to a relative URL such as /sanity ?