Based on my experience, peperomia is quite easy to care for even indoors, where the conditions aren't perfect for it. You just need to place it in a spot where it gets plenty of indirect sunlight and no direct harsh sun, give it a drink only when the surface of the soil is dry because it doesn't like being overwatered, and lastly, make sure it is potted in a mixture that drains water well to avoid the roots rotting. I typically water mine once every 1-2 weeks, and it works wonderfully. Of course, also running the plant in an environment of normal room humidity and making sure it is away from cold drafts is helpful too.