You cannot summon Herobrine in vanilla Minecraft because he is not a real in-game entity
If you want a Herobrine-like experience, install a Herobrine mod or add-on
Download the mod from a trusted source
Follow the mod’s installation instructions for your version of Minecraft
Create a new world or load an existing one with the mod enabled
Use the mod’s specific item, command, or ritual if it provides one
If you are using a custom map, follow the map creator’s instructions
Be cautious with unofficial downloads and avoid suspicious files