A simple script that uses selfcord to send messages to all members of a group chat. Customisable to some extent.
Download code as zip. Drop into some folder.
Fill out information in info.txt
For the token, you will need to use your own account token, which is a bit tricky to do and I won't explain that here. Just google it bro.
Run bot.py and send the word "start" in any channel or DM. You can even just send it to a DM with a bot. This activates the spamming.