I grow my jewel orchids indoors, under LED tube lights (something similar to this). The humidity varies from 50-75%, and the temperature is between 20-35 degrees celsius. I have the majority of my jewels in a mix of sphagnum and small bark, and they seem to thrive, as long as I don’t let the moss completely dry out (watering as needed, once to twice a week in summer, less frequent in winter). I fertilise once every few weeks, with a weak solution of balanced orchid fertiliser.
I also have recently planted some of my jewels in an open terrarium, and they seem to be thriving there, see my terrarium blog post for more details.
How you grow your orchids will depend on your climate, growing space, and your time availability to water and fertilise. The above conditions are what works for me. Below are some links to other posts of what works for other people, that you might find helpful.
http://herebutnot.com/macodes-petola/ – an excellent post discussing humidity vs water availability, and various growing mediums for jewel orchids.
https://travaldo.blogspot.com/2018/04/macodes-petola-care-and-culture.html – some more culture info.
https://gardeningbrain.com/macodes-petola/ – another article on culture requirements.