$results = Process::batch(fn (Batch $batch) => [
    $batch->as('first')->command('bash import-1.sh');
    $batch->as('second')->command('bash import-2.sh');
    $batch->as('third')->command('bash import-3.sh');
])->before(function (Batch $batch) {
    // This runs before the first process is executed.
})->progress(function (Batch $batch, int|string $key, ProcessResult $result) {
    // This runs after each successful process from the Batch.
})->catch(function (Batch $batch, int|string $key, ProcessResult|ProcessFailedException|ProcessTimedOutException $result) {
    // This runs after each failed process from the Batch.
})->then(function (Batch $batch, array $results) {
    // This runs ONLY IF all the processes from the Batch are successful.
})->finally(function (Batch $batch, array $results) {
    // This runs after all the processes from the Batch finish.
})->run();

$results = Process::batch(fn (Batch $batch) => [
    $batch->as('first')->command('bash import-1.sh');
    $batch->as('second')->command('bash import-2.sh');
    $batch->as('third')->command('bash import-3.sh');
})->then(function (Batch $batch, array $results) {
    // This runs ONLY IF all the processes from the Batch are successful.
})->defer();