Because you access an organization by logging in to a personal account, each of your team members needs a personal account. Once you have user names for each person you'd like to add to your organization, you can add them to teams.
Adding users to your organization
- Provide each person instructions to create a personal account.
- Ask for the username of each person you want to give organization membership to.
- Invite the new personal accounts to join your organization. Use organization roles and repository permissions to limit the access of each account.