In future please format your config for the forum: https://community.home-assistant.io/t/how-to-help-us-help-you-or-how-to-ask-a-good-question/114371#oneone-format-it-properly-16 Indentation is important and we can’t see it the way you have posted.
You have spaces where you shouldn’t and you have not quoted your single line template. Try this:
tts_text: "Rafo desconectado de {{ states('sensor.rafo_sm23_wifi_connection') }}"
Yuu can’t put spaces before the parentheses in functions like states()
Good: states('something')
Bad: states ('something')