I will give you as much idea as possible if you think you can make monthly income by trading crypto then you must have good knowledge about the market. At first you invest with a small amount so that you don't break even if you face losses and gradually you increase the amount of money invested. And later you will get your monthly income as a good amount by investing.
Where is this assurance hanged on as to the OP getting back monthly income based on what he must have invested in. Let's be careful not to indulge others into getting themselves in wrong investment deals so they don't end up regretting seeking for help at the first place.
The crypto market is a volatile one and prone to unpredictable circumstances.
Yeah dude there is no assurance he will get profit from investing in hurry without analyzing market and the project that he invest in. I see that the Original Poster is a newbie member, so maybe OP can not yet to do analyzing it easily. Other option beside invest and hold, trade crypto can be another choice, but never start trading crypto already with much amount of money, just start trading with small amount of money if you are not already master in it. To be honest, i do not prefer to suggest a newbie to do trade on crypto without have enough knowledge on market, so OP have to learn more about trading and investing.