If you’re curious to try out RPN/RPL without buying hardware, then both the R47 and DB48x calculators are available as apps on the iOS App Store.
Those of you who want to go deeper down the rabbit hole, I strongly recommend you check out Calculator Culture — he reviews both modern and vintage devices; https://www.youtube.com/@CalculatorCulture
I find them simply difficult to read and use today because of that.
So, I just use a HP48 app on my phone. It's not as good, lacking the tactile response of the keyboard. But it's close.
I used to program the 48's. You think laptops are convenient, wait until you try coding in bed on a 48. Very comfortable, if you can stay awake :).
Did do a fair bit of programming in the 48 too :) fun shit.