iCloud payment
Why am I being asked for an iCloud payment? And why are you questioning my payment details when the last four digits of my current card are being displayed on screen?
iPad Air, iOS 12
You are not talking to Apple. We are mostly users like you trying to help other users.
Regardless, you may be the subject of an attempted scam.
Did you provide any potentially damaging information to anyone? If yes, you'll need to follow up, for example, with a credit card company, Apple, your bank, etc.
If you gave you Apple ID password to a scammer, then
Change your Apple ID password https://support.apple.com/en-us/HT201355
Here is: What to do [before] or after you change your Apple ID or password https://support.apple.com/en-us/HT204071
And see Identify legitimate emails from the App Store or iTunes Store https://support.apple.com/en-us/HT201679
For scam related information from Apple including reporting scams to Apple see Avoid phishingemails, fake 'virus' alerts, phony support calls, and other scams https://support.apple.com/en-us/HT204759