Currently, it is only possible to send a message to a LINE user when they have either:
- added your LINE Official Account as a friend
- sent a message to your LINE Official Account in the last 7 days in a one-to-one chat
LINE will pass an unique contact identity for you to reply to. Note, this unique contact identity is not their LINE ID) and it is not possible to request for any personal information such as LINE ID or phone number of the user.
If you need to verify and merge the user with your CRM, then you can authenticate by asking them to scan a QR code that include their account information. After the authentication, you can update Conversation API via Contact Management API. The authentication is done solely on your system's backend and is not part of Conversation API.
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