Review Apple ID Phone Number for iCloud
After recently upgrading my iPhone to iOS 12 and MacBook Pro to Mojave, the iCloud keeps asking me to "Review Apple ID Phone Number".
On Mac:
On iPhone:
Then if I click it, it will be gone for a few minutes and then come back again. I'm wondering how to disable this annoying notification.
I used to use my iPhone but now I have switched to another android phone, so the sim card is no longer in the iPhone now. I tried insert the sim card back last night and it didn't show up the notification again, however, after pulling it out from the iPhone, the notification comes back.
Please, I don't want to use the old iPhone any more. How can I disable this annoying thing?
[Re-Titled by Moderator]