First, ignore all the PM's requests from people wanting to give you their "genuine and legitimate" business advise. Just don´t fall for that.
Secondly, don´t focus on just one thing. You have enough capital to build a diverse investment portfolio wich is something you should be aiming for in order to reduce risks.
Thirdly...
I have in the past tried dropshipping and it didn't work out, years ago.
This doesn´t mean anything!
Just because you failed in the past doesn´t mean you can make it work. Especially if you have $20k to invest. I strongly suggest you learn as much as you can about it and give it another shot.
There are a few dropshipping courses here you can take a look at that are pretty decent like the one from Gabriel St-Germain.
Unfortunately, the link got removed because it is part of the Do-Not-Share list. But you can browse around and find it. It´s not that hard.
You can also check his
YouTube Channel, the guy gives pretty solid advice on dropshipping.
His channel has "only" 28 videos but over 178k subscribers. Check it out!
If you don´t want to dive into dropshipping again that´s totally fine. There are other ways to make money online like affiliate marketing and CPA.
With your budget, you can pretty easily dive into CPA and blast that baby up with paid advertising
Lastly...
I am a software engineer by trade.
You can research the market and check if there´s a need for a software, develop it and sell subscriptions for it.
Anyway, good luck with this,
Cheers!