Hi there,
Thanks for reaching out. Hope you don’t mind us responding in English, as this is the official language of the Community. Only the owner pays for a Duo/Family plan of course. If you want to join as a member, all you have to do is open the invite sent to you by the owner, log into your account and input the same address as the owner has specified. You should not be asked for any payment information. If you already have an active Individual subscription, joining the Duo plan will automatically cancel it.
Hope this clears things up.
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