How to create a txt file with id chats so that the bot sends messages to these groups, Python Aiogram?

Question

Python

you need to create a txt file (for example, ChatsID.txt), where all chat IDs where the bot is present will be stored. yes, I know there are databases, but I need a txt file, because I have not studied the database yet, and I know chat ids, because all my groups are a local grid. then you need to use this as an argument for sending a message, example:

ChatsID.txt: 100200300, 100300200

bot: sends messages to these chat ids, for example: hello, the bot has been updated