Incoming WebHook

I can successfully send a single text string via internal webhook from vb.net but when I attempt to do any formatting such as add vbCRLF I get an exception- mattermost returns exception 500

I also attempted StringBuilder

      builder.Append("Location: some location")
      builder.AppendLine()
      builder.Append("Person: some person").AppendLine()

How do I format a string for the following layout with line feed?

"
Location: some location
Person: some person
Amount: some amount
"