Why doesn't my cactus grow roots?

It's getting warmer and warmer now. Put it outdoors and in a sunny place. If the soil is very dry and then watered, the water will rot. If it is ventilated outdoors, it will take root in about a month. Don't pull it out often, it will only accelerate death. If you ignore it, just watch it once in a few days. Sometimes I forget to water the cactus for a month. Desert plants like dry environment, and the water is not good.