Merging two apple ids???

Merging Apple Accounts or transferring data is not officially supported, nor can it be done easily or completely.

Apr. 2018 post by ASC helper Winston Churchill on transferring data from one Apple ID to another. https://discussions.apple.com/message/33333380#message33333380

Feb. 2021 tips from Eric Root https://discussions.apple.com/thread/252468781?answerId=254653802022#254653802022

Look into using Family Sharing to continue to be able to use items purchased with one Apple ID with other Apple IDs.

Family Sharing - https://support.apple.com/HT201060

Set up Family Sharing - https://support.apple.com/HT201088

* From an older version of the Apple ID FAQ - https://appleid.apple.com/faq

"I have multiple Apple IDs. Is there a way for me to merge them into a single Apple ID?

Apple IDs cannot be merged. You should use your preferred Apple ID from now on, but you can still access your purchased items such as music, movies, or software using your other Apple IDs."

The FAQ no longer includes this information but neither does Apple provide any documentation telling you how to merge Apple IDs. Strikes me as a kind of a 'don't ask; don't tell' situation.