Cannot get Mail for iCloud

I keep getting the message “cannot get Mail....no password provided for “iCloud”. Please go to Mail Account Settings & enter a password.” This is happening on my iPhone and iPad. At the bottom of the pop-up box it says “OK and Settings”. I select Settings & it doesn’t show me where I can enter my password. I assumed it was using my AppleID. I have the current iOS 14.4 on both devices. I would appreciate any help to solve this as I’m at wits end. My iPhone is the iPhone 11 Pro Max & my iPad is the 12.9 Pro....3rd generation & in the past this had worked fine on both devices.

Thanks.