using consent to choose a channel in a journey

Hi

using OOTB consent object against profile. how can you query the consent choices in a journey to choose the channel to communicate with. So as an example, I opt out of email, then in the journey put a decision in that says 'can i email him, no, then send him down the sms route'. When looking in journey at the fields available for selection, under profile, the consent fields arent there to choose against

thanks