yii2 mandrill邮件已发送但未包含插入

How to insert contain into mandrill template using yii2 nickcv plugin. in this code test.org is my template name and i want to insert into contain. anyone have idea about it. This is the code.

\Yii::$app->mailer
->compose('test.org')
->setTo('test@mail.com')
->setSubject($setSubject)
->send();

i just want to add body like this

$body = "Hi ,Testing here";

You have to use setHtmlBody function just like that

$mailSent = Yii::$app->mailer
                ->compose($template_name)
                ->setFrom('test@mail.org')
                ->setTo($to_email)
                ->setSubject($setSubject)
                ->setHtmlBody($setTextBody['html'])
                ->send();
        return $mailSent;