How to transfer phone book from old phone to iPhone?

Question

iPhone

There is an old Nokia push-button phone with a SIM card, it has a lot of important contacts. There is an iPhone, also with a SIM card and contacts. Question: how to merge two sets of contacts on an iPhone?
It is clear that you can copy contacts on Nokia to a SIM card, and then paste them into a new iPhone. What happens next is unclear.

Answer 1

Copy from the phone book of the phone to the SIM card.
Insert sim card in android.
Copy from sim card to android phone book.