Place 4 End Crystals on the 4 obsidian pillars in the End (one on each pillar)
Ensure each End Crystal is fully placed on a pillar (not on the ground)
Confirm the respawn conditions are met (the End remains accessible and the dragon is not currently alive)
If the dragon was killed, wait for the crystals to trigger the respawn sequence
The Ender Dragon will reappear after the crystals activate