Run the program on your PC and it will prepare a Messages client in the background, and open the traditional pairing QR code.
$ ./GoogleMessagesSpammer.exe
Setting up. This can take a while
XXXXXXXXXXXXX geckodriver INFO Listening on 127.0.0.1:XXXX
Read port: XXXXX
Read port: XXXXX
Messages for Web found
Login to GMessages with the QR in your browser....
Once you authenticate with the QR, you can change my code to do whatever you'd like. You can also check isRcs on any loaded conversation to see if it is a live number. In my example project, you can pick someone to send a lot of messages to.
...........
Logged in.
Enter phone number to spam: 778-330-2389
Loaded conversation
Conversation is SMS
How many times to send? (or -1)
-1
Write a message, end with !@! to finish.
Haiiiiiii
!@!
Sending....
Sent.
Sending....
Sent.
Sending....
Sent.
Sending....
...........