You need to enter your Explaindio Member Account Username and your Explaindio Member Account Password inside Settings of your Explaindio Elements Software. Please make sure you've correctly entered Username and your Explaindio Member Account Password (the same password you use to login to your Explaindio Membership area here: https://account.explaindio.com)
But if you did enter the correctly but if it's still asking you to fill your username/email and password in settings it means you might have a special character in your Explaindio Member Account Password.
Explaindio Elements Validation is special character sensitive. Any special character in password will fail validation.
So, if you get this error, click Lost Password? link to go to your Explaindio Membership area or login to login to your Explaindio Membership area here: https://account.explaindio.com
Click change next to Password and reset your password. Set a new password without any special character in it.
Now go back to Explaindio Elements Software and enter the new password you've set without any special characters inside Settings. Close Settings and this time Explaindio Elements will accept your validation.