It is showing me that the maximum number of free account has been activated on this iPhone

A message saying, "The maximum number of free accounts have been activated on this iPhone" or, "This iPhone has been used to create/setup too many new Apple IDs" is discussed in the support document: "If you see a Could Not Create Apple ID or Could Not Set Up iCloud message." Click on this link to read it. --> https://support.apple.com/HT210743

This message generally means that you have exceeded the number of Apple IDs you can set up with iCloud, or create as new IDs, on a single device in one year. See the recommendations in the link on alternative methods for setting up iCloud accounts, e.g. on a computer, or contact Apple Support if requested:

Click here --> https://support.apple.com/choose-country-region 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 --> https://support.apple.com/HT201232

Create a new ID (if necessary)on another Apple device/computer and sign into iCloud using the same Apple ID on the other Apple device/computer. You should then be able to sign in.

The maximum number of free accounts have been activated    -

Apple ID - create a new.      *

Apple ID – Create       -

Apple ID - Could Not Create or Could Not Set Up iCloud message.    *

Or contact Apple ID Support.  See the Apple Support articles below for contact information.  

Apple ID - Official Apple Support.    -

Contact Apple for help with Apple ID account security - Apple Support.  * (Link doesn’t always load)  

Get Support     -   Work through the screens to get a chat option. You may have to pick a slightly different problem.

Apple Support schedule phone call.  -

https://twitter.com/AppleSupport.  -

Did you read my post above?