Export all tasks to Database

Hello!
I’m creating my custom Dashboard that mixes Asana, Time, and Invoices, and I’m creating a database of a small piece of tasks.

I’ve made a script that recurres projects not archive and then tasks in project. But it gets this error:
offset: Your pagination token has expired.

This is my code in PHP:

foreach ( $asana_projects as $project ) {

	echo 'Project: ' . $project['gid'] . ' Name: ' . $project['name'] . PHP_EOL;
	echo 'Tasks: ';

	// API Pagination.
	$offset = null;
	do {
		$options_call = array(
			'project'    => $project['gid'],
			'opt_fields' => 'gid,assignee_gid,created_at,completed,completed_at,due_at,due_on,modified_at,name,projects',
			'limit'      => BD_LIMIT_API,
		);
		if ( $offset ) {
			$options_call['offset'] = $offset;
		}
		$tasks = get_asana(
			BD_ASANA_API,
			null,
			'tasks',
			$options_call
		);
		if ( ! empty( $tasks ) ) {
			foreach ( $tasks as $task ) {
				if ( isset( $task['gid'] ) ) {
					save_task_db( $task['gid'] );
					echo $task['gid'] . ', ';
				} elseif ( isset( $task['offset'] ) ) {
					$offset = $task['offset'];
				}
			}
		}
	} while ( $offset != null );
	echo PHP_EOL;
}

Get_asana is a function that connects to Asana API.
What am I doing wrong?
Thanks.