Unable to sign into my Apple ID on iPhone

Including basic information in your post will assist us in quickly finding a specific answer to your question. Provide a clear description of what you are trying, where it fails to perform as expected, and the exact wording of error messages. Include your hardware year and model information if you have not already done so in the posting information.

If you can't connect or sign in to iCloud or your account, Apple has a list of things you can try in the document If you can't connect or sign in to iCloud - Apple Support

Is the iCloud server working? --> Apple - Support - System Status

If you are using a VPN, try turning it off and see if you can then log in. E.g., AppStore - Apple Community

If an item is greyed out or restricted, see this support article —> Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support

For more assistance try the iCloud Support web site --> iCloud - Official Apple Support

If you still have problems try official Apple Support. Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world."

Click here --> Contact Apple for support and service - Apple Support