How does Apple 13pro set the SMS verification code to pop up?

You can set it in the password and account column in the settings.

Select Settings in the mobile phone menu, click the password and account number, find the auto-fill password, and click the button at the back to open it. If there is no notification in the SMS verification code notification bar, you can also notify and manage the settings in the settings.

After setting, the SMS will be displayed in the notification bar, and the verification code will be automatically added to the keyboard without copying and pasting.