May I ask, when I booked the tickets for the museum and filled in the email as 163.com, it always prompts "Please enter the correct email". Why is that?

You will be fine if you use your qq mailbox then
There is no problem with the qq email address. I can buy tickets on the same day in time.
I use QQ email, no problem
Please pay attention to the email font, you may have entered Chinese fonts
Maybe you don’t recognize the qq email I use 163
I filled in my QQ email address directly.
You try gmail or apple mail.
The email address may have been entered incorrectly.