смс не работают в РФ
It has limited use elsewhere. Easily forged, easily canceled/censored, the main advantage is operation with very faint signal. There are newer very low bandwidth protocols that should replace it. However, to play around with things that require an SMS, you can use a bridge service. E.g. https://jmp.chat bridges XMMS,SIP, or Matrix to SMS. I recommend XMMS as that keeps minimal server state and a server is very easy to operate, even on less reliable devices such rPi.