How do I connect to a non-default Firestore database using Golang?

I'm trying to connect to a Firestore database named "dbsomething" (non-default) using Golang. However, my current code always connects to the default database. Here is my existing connection code:

GOCopied
firestoreClient, err := app.Firestore(ctx)

Below is the full code snippet I use to initialize Firestore using Golang:

GOCopied
package config

import (
    "context"
    "encoding/json"
    "fatfiresocial/src/logger"
    "fmt"
    "time"

    "cloud.google.com/go/firestore"
    firebase "firebase.google.com/go/v4"
    "go.uber.org/zap"
    "google.golang.org/api/option"
)

func getAndValidateServiceAccount() ([]byte, error) {
    cfg := EnvVariables()

    serviceAccountJSONString := cfg.ServiceAccount
    if serviceAccountJSONString == "" {
        logger.Logger.Error("GOOGLE_APPLICATION_CREDENTIALS environment variable not set")
        return nil, fmt.Errorf("GOOGLE_APPLICATION_CREDENTIALS environment variable not set")
    }

    serviceAccountJSON := []byte(serviceAccountJSONString)

    var temp map[string]interface{}
    err := json.Unmarshal(serviceAccountJSON, &temp)
    if err != nil {
        logger.Logger.Error("Error parsing service account JSON", zap.Error(err), zap.String("serviceAccountJSON", string(serviceAccountJSON)))
        return nil, fmt.Errorf("invalid service account JSON: %w", err)
    }

    return serviceAccountJSON, nil
}

func InitializeFirestore() (*firestore.Client, error) {
    logger.InitialzieLogger()

    ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    defer cancel()

    serviceAccountJSON, err := getAndValidateServiceAccount()
    if err != nil {
        return nil, err
    }

    opt := option.WithCredentialsJSON(serviceAccountJSON)
    config := &firebase.Config{ProjectID: "projectName"}

    app, err := firebase.NewApp(ctx, config, opt)
    if err != nil {
        logger.Logger.Error("Error initializing Firebase app", zap.Error(err))
        return nil, fmt.Errorf("firebase app initialization failed: %w", err)
    }

    firestoreClient, err := app.Firestore(ctx)
    if err != nil {
        logger.Logger.Error("Error getting Firestore client", zap.Error(err))
        return nil, fmt.Errorf("firestore client initialization failed: %w", err)
    }

    logger.Logger.Info("Firestore client initialized for project projectName")

    return firestoreClient, nil
}

This is how I am currently using the Firestore client to save notifications:

GOCopied
func SaveNotification(notification openapi.Notification, db *firestore.Client) error {
    logger.Logger.Info("Saving notification", zap.String("notificationId", notification.Id))

    collectionRef := db.Collection("dbSomething")

    logger.Logger.Info("Saving notification", zap.String("notificationId", collectionRef.Path))
    _, err := collectionRef.Doc("notifications").Set(context.Background(), notification)
    if err != nil {
        logger.Logger.Error("Failed to save notification", zap.Error(err))
        return err
    }
    return nil
}

In my TypeScript project, I could connect to a non-default database like this:

TYPESCRIPTCopied
import { app } from '@config/firebase';
import {
  collection,
  doc,
  getDoc,
  getDocs,
  getFirestore,
  setDoc,
  updateDoc,
  deleteDoc,
} from 'firebase/firestore';
import { getCurrentUser } from '@/lib/api/auth';
import { Community } from '@/types/community';

const db = getFirestore(app, 'guap-social');

What is the equivalent of getFirestore in Golang for connecting to a Firestore database that is not the default?