Trading from countries under US sanctions

Hi all,
I’m so happy to find out about this forum as I have questions which might need a tremendous amount of time to find out about.
A friend of mine requested for some help as he lives in Iran and wants to start FOREX trading. The matter is that since the country is under US sanctions, it is a bit tricky to initiate trading using FOREX brokers available. I want to ask on his behalf if there are any brokers that do not hinder Iranians from trading in FOREX. Furthermore, the broker is required to have high security and with least possible bid/ask spread.