Create new Admin user in WordPress

functions.php

<?php

/**
 * Creates new user with Administrator capabilities
 *
 * Put this code snippet to your theme's functions.php
 * and change $username, $password and $email. The code
 * checks if $username does not exist and creates a new 
 * user.
 *
 * NOTE: This runs on every page load, so don't forget 
 * to comment this code out or remove it after you 
 * create the new user to save load time.
 */
add_action( "init", function() {
  $username = "itsmikita";
  $password = "passwort";
  $email = "[email protected]";
  if( ! username_exists( $username ) ) {
    $userId = wp_create_user(
      $username,
      $password,
      $email
    );
    $user = get_user_by( "id", $userId );
    $user->remove_role( "subscriber" );
    $user->add_role( "administrator" );
  }
} );