Google docs - access data

Question

I want to access the data from public google docs.

https://docs.google.com/spreadsheets/d/12i3Lvwb_14fQES27jVP6baqqmWUXWwM7fZy-neDH3bE/edit#gid=0

The link is working.

The code I'm using:

package main

import (
    "context"
    "fmt"
    "log"

    "google.golang.org/api/docs/v1"
    "google.golang.org/api/option"
)

var docURL = "https://docs.google.com/spreadsheets/d/12i3Lvwb_14fQES27jVP6baqqmWUXWwM7fZy-neDH3bE/edit#gid=0"

func main() {
    ctx := context.Background()

    srv, err := docs.NewService(ctx, option.WithoutAuthentication(), option.WithEndpoint(docURL))
    if err != nil {
        log.Fatalf("Unable to retrieve Docs client: %v", err)
    }

    // Prints the title of the requested doc:
    // https://docs.google.com/spreadsheets/d/12i3Lvwb_14fQES27jVP6baqqmWUXWwM7fZy-neDH3bE/edit#gid=0
    docId := "12i3Lvwb_14fQES27jVP6baqqmWUXWwM7fZy-neDH3bE"
    doc, err := srv.Documents.Get(docId).Do()
    if err != nil {
        log.Fatalf("Unable to retrieve data from document: %v", err)
    }
    fmt.Printf("The title of the doc is: %s\n", doc.Title)
}

It returns 404 not found. What I'm doing wrong?