Click the Invite New User button and enter the email address of the person you wish to grant access.
You can set the level of permissions you want the new user to have, the default is all permissions. These can be limited to certain account features, billing for example for your accounts team.
Click the Send Invite button. The new user will receive an email with the invitation and to setup their login.
Once signed up and logged in, its recommended to setup 2fa to better secure the account.