Companies is the list of customers. A company admin of one of them sees My company instead, and does not see this bar.
The bar at the top is new company. The line beside it says a company is one customer: its own install link, notes, alert rules and schedule. Example Co is already in the list under the bar.
Type the name the way you want it in the company switcher. Create is the next click. The install link is shown once, the same way a new user's password is. This shot stops before create, so Harbour Street has not been added and Example Co is still the only company. Send that link with Send someone the install page.
The page for a company you already have is Company notes, schedule and remote control. Handing someone the commands is Send someone the install page. A person who works the machines is Invite a teammate, not a new company.