Blastengine.init('YOUR_USER_NAME', 'YOUR_API_KEY');

const transaction = Blastengine.transaction();

transaction.fromEmail = 'info@example.com';
transaction.setTo('user@example.jp');
transaction.subject = 'Test subject';
transaction.setText('Test body');
const res = transaction.send();
console.log(res);
// { delivery_id: 188 }

const file = DriveApp.getFileById('DRIVE_FILE_ID');
const response = UrlFetchApp.fetch('https://example.com/logo.jpg');

transaction.addAttachment(file.getBlob());
transaction.addAttachment(response.getBlob());

const res = transaction.send();
console.log(res);
// { delivery_id: 189 }

const bulk = Blastengine.bulk();

bulk.fromEmail = 'info@example.com';
bulk.subject = 'Test subject';
bulk.setText('Text body with  __name__');
const res =  bulk.register();
console.log(res);
// { delivery_id: 189 }

bulk.setTo('user1@example.jp', {
	'name': 'User 1',
});
bulk.setTo('user2@example.jp', {
	'name': 'User 2',
});
bulk.update();

bulk.send();

bulk.delete();