Apple has the Complete Guide support article you need to read about this >>Transfer data from your previous iOS or iPadOS device to your new iPhone or iPad - Apple Support<<
Select one of the three options: Quickstart, iCloud, or iTunes/Finder.
If you need to speak with Apple about this, you can contact them by chat or a phone call. Refer to this page for Apple Support features ➔ Contact - Official Apple Support
Select from the presented options until you find a solution for your issue, or see if there is a chat or phone call contact method offered lower on the page (you sometimes have to narrow down the options multiple times before this is shown). If you do not see your issue, keep experimenting with any series of selections until you reach one that offers a chat session or a telephone call and get the representative to redirect you.
Note that the Chat Link provided in a previous post is only for SMS, not online chat. I suspect it will only work inside the USA. The telephone number provided in a previous post is also only for the USA. This page has WORLDWIDE telephone numbers for contacting Apple for support and service ➔ Contact Apple for support and service - Apple Support