ANSWER:

It is permissible for women to learn from men unless they fear fitnah. It is not permissible for men to watch women as they are instructed to lower their gaze. Women must give dawah to women only. What they are doing defies the purpose of hijab.

https://www.assimalhakeem.net/how-come-hazrat-aisha-ra-used-to-do-dawah-to-men-women-both/

Nowadays we see people watching Islamic lectures on YouTube and most of the time females are the one who watch and listen lectures since most of the time men can go out in a masjid and listen the khutbah or lectures, Is it permissible for women to watch men or for men to watch women who preach Islam just for beneficial means?