How to get the thread_id?

i'm working on an AI agent that can ¹send a message to a new 'prospect' and be able to ²fetch/read a response from that first contact.

so i'm looking this example to send a message:

```
direct = mobile.direct()

direct.send_text("Hello", thread_id)
```
how can i get thread_id, if the thread doesn't exist yet?