APIM send message to Azure Service Bus when backend API is down

apim-to-azure-service-bus-on-api-error.xml

<policies>
        <inbound>
            <base />
            <set-backend-service base-url="https://yourapihere.com" />
        </inbound>
        <backend>
            <base />
        </backend>
        <outbound>
            <choose>
                <when condition="@(context.Response.Body.As<string>(preserveContent:true).Contains("response to check for and perform action"))">
                    <send-one-way-request mode="copy">
                        <set-url>https://{{service-bus-name}}.servicebus.windows.net/{{service-bus-queue}}/messages</set-url>
                        <set-header name="Content-Type" exists-action="override">
                            <value>vnd.microsoft.servicebus.yml</value>
                        </set-header>
                        <set-header name="Authorization" exists-action="override">
                            <value>{{service-bus-shared-access-signature}}</value>
                        </set-header>
                        <set-header name="BrokerProperties" exists-action="override">
                            <value>@{
                                var json = new JObject();
                                json.Add("MessageId", context.RequestId);
                                json.Add("Label", "");
                                return json.ToString(Newtonsoft.Json.Formatting.None);
                            }</value>
                        </set-header>
                        <set-body>@{
                            JObject json = context.Request.Body.As<JObject>(preserveContent: true);
                            return JsonConvert.SerializeObject(json);
                        }</set-body>
                    </send-one-way-request>
                    <set-status code="201" reason="Created" />
                    <set-body template="liquid">
                    {
                        "message": "Created"
                    }
                    </set-body>
                </when>
            </choose>
        </outbound>
        <on-error>
            <base />
            <choose>
                <when condition="@(context.Response.StatusCode >= 400 && context.Response.StatusCode != 401)">
                    <send-one-way-request mode="copy">
                        <set-url>https://{{service-bus-name}}.servicebus.windows.net/{{service-bus-queue}}/messages</set-url>
                        <set-header name="Content-Type" exists-action="override">
                            <value>vnd.microsoft.servicebus.yml</value>
                        </set-header>
                        <set-header name="Authorization" exists-action="override">
                            <value>{{service-bus-shared-access-signature}}</value>
                        </set-header>
                        <set-header name="BrokerProperties" exists-action="override">
                            <value>@{
                                var json = new JObject();
                                json.Add("MessageId", context.RequestId);
                                json.Add("Label", "");
                                return json.ToString(Newtonsoft.Json.Formatting.None);
                            }</value>
                        </set-header>
                    </send-one-way-request>
                    <set-body template="liquid">
                        {
                        "message": "Created"
                        }
                    </set-body>
                    <set-status code="201" reason="Created" />
                </when>
            </choose>
        </on-error>
    </policies>