Is it possible to
require directly file in storage from google cloud function with the same project_id? without creating the HTTP request
Cloud functions can respond directly to change notifications coming from Google Cloud Storage. You can check all the relevant documentation here and an HTTP trigger is not needed.
If what is required is to do some operations with a file (object) stored in Google Cloud Storage using Cloud Functions please refer to the Cloud Storage Client Libraries section. Find an example here using the Python Client for Google Cloud Storage.