If you don't have an account for your company, you have to ask your IMEON reseller/distributor to create an account. You will then receive the login details by email. (Remember to check your "spam" if you have not received anything).
Once you have logged in to your account, you will be able to create user accounts by going to your fleet management interface, "My Installations" tab. Click on the blue "+" button located ath the right of the "User" section, as shown below, and fill in the required information.