same with my son. one advice that really worked for me... stop all electronic exposure like tv, phone, tab etc.... give him books instead. read them out to him with all the singing and dancing.... that will motivate him to speak....

My daughter also started this late but picked up. Had visited a consultant who said there is no problem but since all her work is getting done without speaking, she is not making the effort. So he asked me to stop doing her favourite things till she would not speaking and asking for it. This worked wonders for me

encourage speech by talking and showing objects to baby, describe all activities you are doing, reduce screen time if baby watches them... you could talk to paediatrician about it...