Can I send messages to people without an associated phone number? (Unidentified/sealed senders)

[dneu]

I can receive messages from them, but I can't send messages from them. Here's an example of a received message:

Envelope from: “<username>” <user's uuid> (device: 4) to <my phone number>
Timestamp: 1726687211583 (2024-09-18T19:20:11.583Z)
Server timestamps: received: 1726687209731 (2024-09-18T19:20:09.731Z) delivered: 1726688067428 (2024-09-18T19:34:27.428Z)
Sent by unidentified/sealed sender
Message timestamp: 1726687211583 (2024-09-18T19:20:11.583Z)
Body: <their message>
With profile key

[AsamK]

You can just use their uuid (<user's uuid>) instead of their number when sending a message.