I'm not familiar with 433Utils, but it looks like it's a basic library for sending short command codes rather than transmitting data. It looks like it sends integer values as the command codes.
Presumably you could use that to send whatever data you wanted as long as the client and server are talking the same language, but it's going to be very slow for anything above very short strings.
If you want to send a string as a series of integers (which will be very inefficient) then you can convert your string into bytes ( https://docs.python.org/3/howto/unicode ... g-to-bytes
) then send each byte as though it was a command, but then convert it back into a string at the other end.