A free domain was included in my package, but I cannot find where to sign up in the portal

Once your company is officially registered with Companies House, you’ll receive an email confirming your order, including a special link to the IONOS site. You can use this link to claim your free .com or .co.uk domain or choose to add a hosting plan to your cart for just £1 per month. Please note: The .com or .co.uk domain is free for the first year, but this offer is only valid through the link in your order confirmation email. The discount applies only to the first year, and renewal fees are not included. Standard terms and conditions apply.