I phone use in a different country from US

I don't see an Iranian carrier on the list that supports eSIMs, you might be able to use an international eSIM from your American carrier but I would check with them first.

Use eSIM while traveling internationally with your iPhone - Apple Support

Apple does not do business in Iran. There are no supported carriers at all in Iran. In fact, it is illegal to give or sell any Apple product to anyone who intends to take it to Iran.

Iran is still under international sanctions. Contrary to what your media tells you, the sanctions have NOT been lifted.

You're welcome, good luck!