Schema

{
    "title": "MatrixNotificationHandler",
    "type": "object",
    "properties": {
        "homeserver": {
            "title": "Homeserver",
            "type": "string"
        },
        "room_id": {
            "title": "Room Id",
            "type": "string"
        },
        "username": {
            "title": "Username",
            "type": "string"
        },
        "password": {
            "title": "Password",
            "type": "string"
        },
        "routing": {
            "title": "Routing",
            "default": {},
            "type": "object",
            "additionalProperties": {
                "type": "string"
            }
        }
    },
    "required": [
        "homeserver",
        "room_id",
        "username",
        "password"
    ]
}

Configuration - matrix