Ways to motivate a non verbal 3 year old to want to communicate


My little boy is going through the diagnosis process at the moment. This post relates mainly to speech therapy, we’ve been told he needs specialised speech and language therapy because he is non verbal and he is not motivated to communicate or even want to learn to. 

Has anyone else been in this position and can give me some tips and ideas on how to motivate him?

Speech and Language therapy won’t even consider us for one to one or group sessions as they say it’s pointless when he doesn’t have the foundations to want to communicate. 

Any help greatly appreciated