Rasa doesn't pass all the instructions from credentials.yml to Twilio


I’m trying to create a voicebot using Twilio, since Rasa already has a webhook for it. In my credentials file I have this:

twilio_voice: initial_prompt: “start” assistant_voice: “Polly.Ewa” language: “pl-PL” reprompt_fallback_phrase: “Nie zrozumiałam. Mógłbyś powtórzyć?” speech_timeout: “1” speech_model: “default” enhanced: “false”

which are basically TwiML instructions, meaning what Twilio does after receiving the answer from Rasa. The problem is, the language attribute is the only one that doesn’t get passed, so the Twilio STT understands my words wrong, because it transcripts it to English instead of Polish. I know my question might be out of Rasa topic, but it would be great if anyone has any experience with doing something similar and would be able to help me.


One more thing.

I just saw in rasa.core documentation, that the language tag isn’t even supported:

So right now this is going to be even harder than I expected. Any help would be greatly appreciated. I think I need to edit the twilio.py file in Rasa, but I’m not sure how can I do that.