tell me the duo joining secrets please

To ensure the sign-up and invitation acceptance process goes smoothly, please check the following key requirements:

The invitee must have a free account version (Deezer Free): If the invited member currently has an active paid subscription (Premium), Deezer will block the link-up and display a generic error message during sign-up. The invitee must cancel their subscription and wait for it to expire completely (so the account reverts to "Free" status) before clicking the invitation link.

Logging in with existing credentials: If the invited member already has a free account, they should select the login option after clicking the link and enter their existing email and password. If they do not have an account, they must select the "Sign up" option on the same screen and create a brand-new password.

Link expiration: Deezer Duo invitation links are valid for 30 days. If this period has passed, the system will report an error, and the plan administrator will need to send a new invitation.

How to resolve login issues?
Have the invited member first try logging into the Deezer website normally using their usual credentials (independently of the invitation link) to verify that the email and password are correct.
If the password has been forgotten or the system reports an error, use the "Log in without password" option on the Deezer login page to have a direct access link sent to their email. Once they have successfully logged into their Deezer Free account in the browser, have them click the Duo invitation link again.