Sendmsg

const response = await fetch('/api/RDS/Host/{rdsId}/sessions/{id}/sendmsg', {
    method: 'POST',
    headers: {
      "Content-Type": "application/json; api-version=1.0"
    },
    body: JSON.stringify({}),
});
const data = await response.json();

{
  "type": "text",
  "title": "text",
  "detail": "text",
  "instance": "text"
}