Invest in a crypto market situation accordingly. There should be a framework for him to invest in which time to invest. And at what time to sell.
This is unlike the real stock market, there are differences in the crypto trade and the stock exchange. I guess you should try to learn it.
and for now the level of risk to invest is very large, unless you invest in the long term. and however here it involves knowledge and experience so you should first start looking for it first.