HubIQ provides email sending but doesn't provide email inboxes. Many people create email inboxes using Google Workspace (also known as GSuite) or they use an email inbox from their domain provider such as Godaddy or NameCheap.
You can still send emails from the same email address as your email inbox however replies will go directly to your Inbox not HubIQ. Sometimes companies send automated outbound emails from an address like "no-reply@domain.com" when they dont need to get replies to outbound emails like for announcements.