Long time ago Riseup, focused on activists, required two invite codes, probably to avoid abuse. They’ve relaxed it with asking for only one invite code. You should imho not be asking for invite codes on the Internet but ask your activist friends or read this : https://support.riseup.net/en/knowledgebase/1-accounts/docs/13-how-do-i-get-an-account
Long time ago Riseup, focused on activists, required two invite codes, probably to avoid abuse. They’ve relaxed it with asking for only one invite code. You should imho not be asking for invite codes on the Internet but ask your activist friends or read this : https://support.riseup.net/en/knowledgebase/1-accounts/docs/13-how-do-i-get-an-account