So if he's getting the money from his father who is not interested, no need to force them to invest. Your friend should start doing some gigs online or if he's young enough to get an actual job, go for it and invest out of it. And meanwhile, keep telling his father about the benefits of Bitcoin and what decentralization is and how it's saving people in country where the inflation is sky rocketing. Good Luck!
The benefits of bitcoin are undeniable. But in this case, the benefit of bitcoin will be nothing compared to his work. So no need to explain to his dad about bitcoin, what his dad said just wanted good for him. Bitcoin is a banned asset in their country, and he is a government employee with a very high salary. And if he quits his job to invest in bitcoin, there is no guarantee that bitcoin will bring him more than he already has.