How do I get my husband open to having baby #2?

Many many years ago when my husband and I were still in the first few years of dating, we agreed that we wanted 3-4 children. We had baby #1 in January and we are both over the moon about her. I want to go ahead and talk about the next one. Not start trying or anything, but to just have a plan or a general outline of when would be a good time to stary trying or to have #2. He now suddenly says that he's not sure if he wants another at all.

Neither of us ever wanted an only child. We had countless discussions about it before trying for #1, while trying, while pregnant, and up until she was born. He never even hinted about only having 1 baby, so I've been completely blindsided.

I still want at least 3 children, and I'm not ready to give up that dream. I know that we have plenty of time for his mind to change or maybe even my mind to change. I still can't picture myself with only 1 child though.

I don't want to "convince" him to have another baby, because I want him to want our next one. But I don't even know how to talk about it anymore. I feel like he gets so annoyed whenever I bring up having another baby in the future. Even if I make it clear that I'm not talking about right now, it feels like he's annoyed by the tiniest mention of babies.

So I guess I'm asking how to get him open to the idea of having another. Preferably within the next 2 years.