RocketChat PostMessage using attachments fields

Question

i'm trying to send a custom message using attachments fields

{
  title: 'Markdown Test',
  value: '`hi`',
  short: false
},
{
  title: 'Markdown Test',
  value: '```hi```',
  short: false
}

But when I recieve this message at the brower the markdown is not rendered.

I noticed the inline_code and the multi line code markdown is not been rendered.

What i'm doing wrong?

Best regards, Amandio Magalhaes