You will get a message from JFT_BOT letting you know when your registration is confirmed. It will also be announced in #techsupport.
You may then click "I have a password" in Kiwi and put your password in the second box.
If you don't get the email or can't complete these steps successfully, your request to register your nickname will expire in 24 hours.
If you're an IRCCloud user please https://static.neveraloneclub.org/irccloud.html for a guide that shows where to put your password.