.store.bucket.get is not a function

i’m trying with couchbase “3.2.4” and node js “16.14.3” for reading attachments form couchbase

        mainModel.store.bucket.get(imageKey, { xattr: true }, function (error, response) {
            if (error) {
                return reject(new Error(error.message));
            }
            result['value'] = response.value;
            return resolve(result);
        });

this above piece of code not working and this used work earlier with lower version node js and couchbase
kindly help for how to read attachemtns from couchbase with node js sdk