interfacing arduino to smart meters for token recharge

hello, i am off building a circuit that will enable customers to top up/recharge their smart meters via SMS. workdone so far is that i been able to receive sms sent from mobile phone and parse it , extracting required token digits but now i am stuck, its my wish to interface my arduino with the meter so the tokens could be sent straight up via RF or PLC but i dont know how to achieve it.

i read tech parameters of the meter which supports RF, PLC and Cable communications, my opt is PLC or RF.

this is the meter https://clouglobal.com/product-126.html that i have at home

anyhow to achieve this please, will be greatly appreciated