If he only replies when you start the chat, do this

The useful question is not whether he replies. It is how often he starts something. Scroll back through the last few weeks and count the conversations he opened. If the number is zero, or he opened one and it fizzled, that tells you more than any single message he sent.

Also look at what his replies contain. A reply that answers your question and adds a small detail is someone who is engaged but not driving. A reply of one or two words with no question back is someone answering because you asked. Pay attention to whether he picks up threads you left open, like asking how something turned out. People who like you tend to remember what you said, even if they never bring it up first.

Most of the work sits in the last line of your message. If it can be answered with yes, no, or lol, he will do exactly that and the thread stops. Pick something specific from his life, a plan he mentioned, a place he likes, something he complained about last time, and attach one clear question that needs an actual answer.

Then keep your own part short. Two or three sentences with one question is enough. Long paragraphs about your day can make him feel he has to match your effort, and that often gets a shrug. Don't stack two questions, because he will answer the easier one and skip the other. Also avoid asking him to explain his texting habits. That turns a casual chat into a conversation about him not texting, and he is likely to get defensive or go quiet.

Timing matters more than most people expect. If he usually replies within a few hours, a full day of silence after your message is a signal, and it's a good point to let things sit. Sending a follow up the same evening reads as chasing, even when the first message was fine. Give it at least a day, then resume with something new rather than repeating the first message in different words.

If he never answers, make one more attempt spread over about a week. That message should be casual and easy to ignore, with no reference to the silence. If he still doesn't respond, you have your answer. Keep the thread open in case he writes to you on his own later, but don't keep messaging to see if he changes. Notice whether he reaches out in the week after you stop, because that tells you a lot about whether the silence was a habit or a choice.