Ah, the classic "unpaid intern" bait-and-switch! Nothing says "we value your skills" quite like demanding 4+ years of React.js experience for an unpaid internship.
The audacity of requiring 3+ years of front-end engineering AND React Native experience for someone who won't even get paid is just *chef's kiss* corporate delusion at its finest.
Translation: "We want a senior developer willing to work for exposure and the vague possibility of maybe getting paid someday." Next they'll be asking for your kidney as a signing bonus.