i need advice about getting a second job?

[T]

I am a mechanical engineer & work in power plants for more than 8 hours a day
but inflation and high cost of living in iran & for to pay scholarship my sister & broder i need a second job
then i need advice about getting a second job? low risk & not need to spend a lot of time

[pizza]

Food delivery driver. Some risk of being robbed, but not too dangerous. Listen to your own music, keep your tips, work at night...

Taxi driver. My dad's friend actually bought a taxi from a company, drove during the night, and rented it to his friend to drive in the day to earn money all while working during the day. He bought another taxi and another, now he owns a fleet of them and has his own little company.

Web designer. Work from home on your own time. When I was teen, I used to design social network profiles on Photoshop for money. I also designed some ads, but not too many. I made some good money. I earned enough to buy a used car in a year of free lance on & off again design.

If your sister and brother are old enough, why not ask them to try and get part time jobs? If they are over 16, I do not see why not. If they are under 16, I definitely understand.