Redirect from non-www to www

Previously i am using v3 so created new server and installed v4. Installed new wordpress with easyengine V4.

ee site create www.example.com

Latest i used all in one migration to import content from old site to new.

now when i enter example.com [http or https] it is not redirecting to www.

what i need to do.

are you sure A record is set for www ?