If you have your Easy Affiliate registration type set to “Private”, then your affiliates won't be able to register themselves. Instead, you'll need to add them manually.
Because Easy Affiliate uses the WordPress platform, it's incredibly simple to manually add an affiliate user to your affiliate program. Simply head to your WordPress Dashboard > Users > Add New page and enter in the username/email and other profile details for the new affiliate user.
Click “Submit” to create the new user in WordPress.
After the user is created, go back to the Users page and search for the new user. Hover over their username and click “Edit”.
Scroll down to the Affiliate Settings section and check the “Is this user an Affiliate?” checkbox, then save the user's profile.
The user will now be an affiliate. You'll most likely want to email them directly afterward to let them know where and how to log in to your affiliate dashboard.