80304: Not Found Unmanaged Identifier

Twilio returns this warning when Proxy cannot find the unmanaged proxyIdentifier you supplied for a Participant. In Proxy, a Participant identifier can be a phone number or a channel identifier. If you set proxyIdentifier yourself, it must be a valid proxy address for that Service. For phone-based flows, that means a Twilio phone number already available to the Service. For channel-based flows, that means a configured channel sender managed through your Proxy channel setup.

• You supplied a non-phone proxyIdentifier for a channel that is not installed or configured for Proxy. Proxy channel integrations must be installed in Console before you use a channel sender as a proxy identifier.
• The channel Callback Url is not set to your Proxy Service webhook, so Proxy is not managing that channel sender for the Service.
• The identifier or proxyIdentifier does not use the expected channel address format. For channel-based Proxy sessions, the Participant identifier is the end user's channel ID and the proxyIdentifier is your channel sender ID.
• You specified a phone number as proxyIdentifier, but that Twilio phone number is not already added to the Proxy Service number pool. When you provide a phone-based proxyIdentifier, Proxy only accepts a Twilio phone number that is already associated with the Service.

• If you are creating a phone-based Participant, add the Twilio number to the Proxy Service number pool before you set it as proxyIdentifier. You can also omit proxyIdentifier and let Proxy select an appropriate number from the pool.
• If you are creating a channel-based Participant, install the channel in Console and set the channel Callback Url to your Proxy Service webhook.
• Use the correct values when you create the Participant. Set identifier to the end user's channel ID, such as messenger:+1415XXXXXXX. Set proxyIdentifier to your channel sender ID, such as messenger:{page-id}.
• Verify that you are using the correct ServiceSid. Proxy number pools and channel management are configured at the Service level.

• Using Proxy with Channels
• Participant resource
• Service resource