How to type the symbol mu (micro) on an iPhone

I am teaching electricity and I am using a Quiz programme to take tests. In some questions the answer should contain the Greek symbol µ for micro, as in µA for microampère. I read that µ is available on the Greek keyboard, but I don't want de pupils (age 13-16) to install the Greek keyboard on their iPhone.

Does another solution exist with a regular US or preferable French keyboard?

Thanks,

Jos