You can add a new account to your organization. Under Administration - Account you get an overview, which accounts are already in your organization, along with other information that can be adjusted by clicking the Columns button.
To add a new account to the organization, firstly click on the Invite button. This action will open a window, that allows you to enter the email of the account you want to add, the role the account has, as well as how long you want it to be valid, if there is a time limit.
Once you click the button, you will see, that the invite is pending:
The new account user gets an email with a button Accept Invitation, that must be clicked to link the account with the organization.
If the account already exists, that’s it, the account will be in the organization. Otherwise the user will see the following screen and has to create a password for the new account.
Either way, if you check the table in Administrator - Accounts again, the new user should also be in the table.