They make games where you have to spell words quickly or you lose and that’s how I learned as a kid.

Like one where you’re in a spaceship and have to shoot lasers at asteroids that are coming at your ship. You have to spell the word that’s written on the asteroid to hit it with a laser.

Idk if any of them are free but they’re basically simple coded flash games so I’m sure you could find one on the internet pretty easily