My iPhone 7 is searching for network

See if this recall applies to you: iPhone 7 Repair Program for "No Service" Issues - Apple Support

Well, assuming that is the problem there is no easy solution for you. That's one of the problems of buying any product in a location that has no support options for it. I certainly have sympathy for your situation, and believe it is unfair that Apple is not permitted to do business in Iran, but all I can suggest is to send the phone to a friend in the country where it was purchased and have them take it to an Apple store or ship it to Apple.

If the phone was purchased in Dubai an Apple Authorized Service Provider should be able to fix it. If it was purchased anywhere in the European Union you can send it to Romania, as it is a member of the EU, and Apple offers support in any EU country for a phone purchased in any EU country.

Talk to your carrier as they control the signal strength.

Thanks but I live in Iran and here is not apple center

What can I do now ?

I have friends in Dubai an Romania I can sent it to them . They can fix my problem ?

My iPhone serial number in A1660

I have not body in the china

That model is sold in the US and China. Most likely the US is where your phone came from.

thanks friend

I probably will send an iPhone to Romania, I have no other way, and I do not have anyone in America or China
Thank you for the information I provided