Click on the phase to which you want to add individual participants. On the selected phase :

Select the Participants tab
Click on the Import participants button
Upload your file containing the participants. This file must respect the following column format:
- email or login* | team name
  (Leave the team name blank to create an individual entry)
You can download a sample file click here
Click on Import.
You can check which participants will be imported into your challenge.

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Upload your file containing the new participants. This file must respect the following column format:
login* | email | first name | last name
You can download a sample file click here
Click on Import.
You can check which participants will be created.
Once the users have been created, you can try again to import the participants into your challenge.

* The login field is in most cases identical to the email, but some schools provide different logins from the emails. You can usually retrieve this information by exporting your course users from your LMS.

How to modify your challenge?