yitzhak1029,
Were you able to follow the steps in the article that was recommended to see if they resolve the issue?
"Get help signing into iCloud
Before you begin, check the Apple System Status page to make sure there are no outages or scheduled maintenances currently affecting iCloud and make sure that you’re signed in to iCloud with the same Apple ID on all of your devices.
If you can't remember your Apple ID or password
If you can't remember your Apple ID, check these settings and services to find it. If you've forgotten your Apple ID password, learn how to reset it.
If you get a message that your Apple ID is locked or disabled
If you or someone else enters your password, security questions, or other account information incorrectly too many times, your Apple ID automatically locks to protect your security and you can't sign in to any Apple services. Learn how to unlock your Apple ID.
If you can't sign in to iCloud.com
Learn what to do if you have trouble signing in to iCloud.com.
If you're not able to sign in using cellular data only
Make sure that your iPhone, iPad, or PC has a strong Internet connection and that you've turned on cellular data on your iPhone or iPad by going to Settings > Cellular or Mobile Data. If this setting is off, you might not be able to access your Apple ID and iCloud when not connected to a Wi-Fi network.
If you're having trouble receiving verification codes, or your verification code is rejected
Learn how to get a verification code and sign in to iCloud with two-factor authentication. If your device is running iOS 8 or OS X Yosemite or earlier, sign in using two-step verification instead.
If you see a Could Not Create Apple ID or Could Not Set Up iCloud message
If you see one of these messages, it means that you have exceeded the number of new Apple IDs you can set up with iCloud on a single device in one year. Learn what to do.
Other password prompts you might see
If you are repeatedly prompted to enter your Apple ID password on your Mac or iOS device
If you want to sign in to a third-party app but your password is rejected
If you want to access your iCloud information from a third-party app, you need to use an app-specific password. This helps protect your account by allowing you to sign in securely. Learn how to create and use app-specific passwords.
If you still need help
If you still need help signing in to iCloud, update your iPhone, iPad, and iPod touch to the latest version of iOS or iPadOS, and your Mac to the latest version of macOS. See the iCloud system requirements for more information."
Cheers!