Air China didn't send an e-ticket number message. Is there a problem?

Is that okay? Just show it online. After logging in, check my reservation. There will be one.

Not long ago, I booked two tickets, one was notified by SMS, and the other was not, but there was no ticket number, so there was no problem.

As long as your information is correct and you don't enter the phishing website, there is no problem. Just book a plane ticket at the airport.