Carnivorous plants like the Venus flytrap have evolved to grow in low nutrient soil. That’s one of the reasons they’ve adapted to catch insects in the first place - bugs can supplement the little nutrition the plants obtain through their roots. Normal potting soil is not suitable, and some species can even be killed by common fertilisers.
The mixtures I’m selling here are specially formulated for carnivorous plants, and are comprised of varying ratios of fine grade Irish moss peat, Cornish washed granite sand, perlite, orchid bark, and sphagnum moss. See delivery information.