my iPhone lost network

Mobile network coverage is provided by a mobile carrier. (Apple does not provide this coverage)

Once you establish service with a carrier, the network and account particulars are programmed into your phone with a SIM (or eSIM).

Hello,

Hmm, I'm not sure what you are asking, but start here:

If you see No Service or Searching on your iPhone or iPad

If your issue is something else, please provide more detail.

Good luck.