When you say he’s not opening his mouth, is that to you putting the food there? Presumably you’ve tried putting things on the tray/plate and letting him help himself? Could try something messy like yogurt/houmus and just let him have fun with it with his hands without using a spoon x
Have you tried the food dummies? You could put some fruit or yoghurt in to get him used to the taste then if he gets on with them try the real deal?
Mine was the same, she started taking yoghurt and bananas at first and now she’s doing well, I just kept trying and a different times of the day and one day it just clicked
My lb wasn’t great at first and still a little hit and miss now. I find what helped was popping a bit of the food on his lip - I’m not talking force feeding but dabbing a little with the spoon, my finger, a dummy. Whatever he will take calmly. Once he tasted it he would eat loads. Now if he won’t eat I pretend to eat his food and all of a sudden he wants it. We usually eat at the same time so sometimes I’ll give him food off my plate too. I was very upset in the beginning but now he gets excited to eat. It takes a lot of patience but try not to worry x
Doesn't have to be two meals yet, but do let your GP know. Ultimately keep trying! Make it fun but also limit distractions . Airplane/train/postman stories! Are you eating at the same time as your LO? Have you tried a different time of day? Breakfast or lunch time?