I am getting a new iPhone. How do I transfer my apple cash

I just did this a week ago..

I used Quick Start to transfer all my content from previous iPhone to new iPhone.

There were prompts that guided me thru everything, including Apple Pay items.

When it was done, my new iPhone was basically a replicate of my previous iPhone, including Apple Cash.

Transfer data from your previous iOS or iPadOS device to your new iPhone, iPad, or iPod touch - Apple Support