Email trigger how to attatch file from storage?

[elfasito]

Hello people
Im triying to send a email with an attatchment from firebase storage using email trigger extension.
I have working the email trigger extension to send emails using a gmail smtp.

this is my code (c#):

        Dictionary<string, object> docData = new Dictionary<string, object>
        {
            { "to", "[email protected]" }
        };

        Dictionary<string, object> MessageObject = new Dictionary<string, object>
        {
            { "text", "holis desde unity" },
            { "subject", "Email desde unity" },
        };

               Dictionary<string, object> AttatchmentObject = new Dictionary<string, object>
        {
            //{ "filename", "image.png" }, //this work
            //{ "path", "https://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png" } //this work
            { "filename", "image.png" },
            { "path", "gs://myDirectory/[email protected]/image.png" }
        };

        docData.Add("message", MessageObject);
        MessageObject.Add("attachments", AttatchmentObject);

        dbfirestore.Collection("email").AddAsync(docData).ContinueWithOnMainThread(task => {
            DocumentReference addedDocRef = task.Result;
            Debug.Log(($"Added document with ID: {addedDocRef.Id}."));
        });

the email not is sended I get this error in firestore:
Error: ENOENT: no such file or directory, open 'gs://myDirectory/[email protected]/image.png'

How I can access to a file from storage?, from email trigger.
Also attatch a file from a public URL is working fine.