non www. redirects to wp-signup

http://axiom-online.co.uk redirects to https://www.axiom-online.co.uk/wp-signup.php?new=axiom-online.co.uk

e.g https://www.axiom-online.co.uk is working normally only https://axiom-online.co.uk (non www. is being redirected)

FYI: http://www.axiom-online.co.uk is the primary domain