Fetch upload streamsThe fetch() method and Request() constructor accept a ReadableStream object as the request's body option, to stream upload data to the server.fetchFetchlimitedhttps://fetch.spec.whatwg.org/#concept-body-streamhttps://developer.mozilla.org/docs/Web/API/Request/bodyapi.Request.Request.options_parameter.body.accepts_readablestreamapi.Request.bodyapi.fetch.options_parameter.body.accepts_readablestreamhttps://nowyoucanuse.com/features--fetch-request-streams.html