M1: Create admin user (External script)

create-admin.php

<?php
require_once('./app/Mage.php');
umask(0);
Mage::app();

try {
    $user = Mage::getModel('admin/user')
        ->setData(array(
            'username'  => 'developer',
            'firstname' => 'John',
            'lastname'    => 'Smith',
            'email'     => 'john@example.com',
            'password'  =>'admin123',
            'is_active' => 1
        ))->save();

} catch (Exception $e) {
    echo $e->getMessage();
    exit;
}

//Assign Role Id
try {
    $user->setRoleIds(array(1))  //Administrator role id is 1 ,Here you can assign other roles ids
        ->setRoleUserId($user->getUserId())
        ->saveRelations();

} catch (Exception $e) {
    echo $e->getMessage();
    exit;
}

echo "User created successfully";
?>