To be able to invite members to your Divi Team, you must first purchase team seats.
How to Purchase Team Seats
Log in to your Elegant Themes account
Click on the Team tab
Click on the Add Team Seats button
Choose how you would like to be billed (Monthly or Yearly). If you choose Yearly, you will receive a discount
Choose how many seats you need
Click on the Proceed To Checkout button
Invite Members
Once at least one seat has been purchased, you can invite members to join your Divi Team.
Log in to your Elegant Themes account
Click on the Team tab
Click on the Invite Member button
Fill in the form with the member's details: First name, Last name, and Email address, and choose the member role using the Role dropdown
Click on the Send Invite button
Confirm Divi Team invitation
An email containing the Create Account link will be sent to the designated email address. The new member will be added to your Divi Team, having its status of Pending, until the user confirms the invitation and creates his own account.
Note: The user you are inviting doesn't have to own an Elegant Themes account.
Clicking on the Create Your Account button in the Invitation email will redirect the user to the Account Creation page:
Once the account has been created it will be listed in your Members list as Active.