I’m worried that my 18 month grandson has a learning difficulty. He’s not speaking or pointing or making eye contact babbling He doesn’t respond to his name . They need to get him to a doctor .

I understand your worry about your grandchild, but the others are right. I would keep quiet and wait for it to be raised. I had the same worries about my grandson for the same reason. He is now 19 and in his second year at Uni.

Not. Your. Child. You really need to keep out of it. He will have been assessed by a health visitor, albeit remotely. There are countless charts identifying the range of skills at each age. My dgs babbles constantly, doesn't always make eye contact, rarely answers to his name and is 18 months. He is progressing normally, he is bright and inquisitive and happy. And if your grandson has a problem, then his parents will deal with it, not you. I'm sorry if you feel this is harsh and I'm sure you are only concerned but no good can come from you interfering.

"They need to get him to a doctor." No - they need to make their own decisions about their child.

You don’t. Even if he is on the spectrum there is no cure and so no reason at present to rush him anywhere.
As the parents they will asses the situation and make decisions as a team. These conversations may not involve you and you may not be informed of them.
For all you know they could be in touch with the HV.

And also. May children develop differently. And at 18 months he is way to young to be over analysing his behaviour.