The Praxis have a 110BCD, so in theory you should be able to use other chainring, however I do recommend sticking to Praxis' own, as they work really well and a worthy alternative to Shimano offering (especially since they come down to 48/32 using their chainring and bolt).
Some chainrings are designed for hidden chainring bolts where the chain drop prevention pin is not in the expected place. (Eg Sram force/red chainrings).
I have a praxis chainset & bb that i quite like - am i stuck using praxis chainrings or are there other chainrings that I could use?