I am working on Mulesoft Integration module Automate Order-to-Cash Process Using MuleSoft Flow Designer, while on step Trigger SMS Using the Twilio Connector, STEP 7 indicates  copying following code:
Body: "Order for " ++ vars.OppDetails.Name ++ " has been placed.
Details:
" ++ "OrderID: " ++ payload.OrderID as String ++ ", Tracking: "
++ payload.TrackingNo ++ ", ETA:" ++ payload.ETA as Date
The above code in the transform indicates error in Anypoint Platform:
Error: event:22c3f4a0-382e-11ea-b070-02766eec795c ********************************************************************************Message               : "You called the function 'Value Selector' with these arguments:   1: String ("payload" as String {encoding: "UTF-8", mediaType: "*/*; charset=UTF-8", mime...)  2: Name ("Id")But it expects one of these combinations:  (Array, Name)  (Array, String)  (Date, Name)  (DateTime, Name)  (LocalDateTime, Name)  (LocalTime, Name)  (Object, Name)  (Object, String)  (Period, Name)  (Time, Name)5|   OppId: vars.OppDetails.Id,            ^^^^^^^^^^^^^^^^^^Trace:  at main (line: 5, column: 10)" evaluating expression: "%dw 2.0output application/json  ---{  OppId: vars.OppDetails.Id,  OrderAmount: vars.OppDetails.Amount,  orderdate: vars.OppDetails.CloseDate,  productInfo: {    productID: payload[0].productID,    category: payload[0].category,    SKU: payload[0].SKU,    productName: payload[0].productName,    inventory: payload[0].inventory  }}".Element               : salesforce_to_twilio_connector/processors/2 @ ordertocashautomation-updu:mule-config.xml:38 (Transform)Element XML           : <ee:transform doc:id="069f6d19-8dbc-4dbb-ad0c-fe9fe9e40bf2" doc:name="Transform" doc:timestamp="1579157186684">                        <ee:message>                        <ee:set-payload>%dw 2.0                        output application/json                          ---                        {                          OppId: vars.OppDetails.Id,                          OrderAmount: vars.OppDetails.Amount,                          orderdate: vars.OppDetails.CloseDate,                          productInfo: {                            productID: payload[0].productID,                            category: payload[0].category,                            SKU: payload[0].SKU,                            productName: payload[0].productName,                            inventory: payload[0].inventory                          }                        }</ee:set-payload>                        </ee:message>                        </ee:transform>Error type            : MULE:EXPRESSIONFlowStack             : at salesforce_to_twilio_connector(salesforce_to_twilio_connector/processors/2 @ ordertocashautomation-updu:mule-config.xml:38 (Transform)) 125 msPayload Type          : org.mule.runtime.core.internal.streaming.object.ManagedCursorIteratorProvider--------------------------------------------------------------------------------Root Exception stack trace:org.mule.runtime.api.el.ExpressionExecutionException: You called the function 'Value Selector' with these arguments:   1: String ("payload" as String {encoding: "UTF-8", mediaType: "*/*; charset=UTF-8", mime...)  2: Name ("Id")But it expects one of these combinations:  (Array, Name)  (Array, String)  (Date, Name)  (DateTime, Name)  (LocalDateTime, Name)  (LocalTime, Name)  (Object, Name)  (Object, String)  (Period, Name)  (Time, Name)5|   OppId: vars.OppDetails.Id,            ^^^^^^^^^^^^^^^^^^Trace:  at main (line: 5, column: 10)    at org.mule.weave.v2.el.WeaveExpressionLanguageSession.doEvaluate(WeaveExpressionLanguageSession.scala:130)    at org.mule.weave.v2.el.WeaveExpressionLanguageSession.evaluate(WeaveExpressionLanguageSession.scala:77)    at org.mule.weave.v2.el.WeaveExpressionLanguageSession.evaluate(WeaveExpressionLanguageSession.scala:103)    at org.mule.runtime.core.internal.el.dataweave.DataWeaveExpressionLanguageAdaptor$1.evaluate(DataWeaveExpressionLanguageAdaptor.java:252)    at org.mule.runtime.core.internal.el.DefaultExpressionManagerSession.evaluate(DefaultExpressionManagerSession.java:38)    at com.mulesoft.mule.runtime.core.internal.processor.SetPayloadTransformationTarget.process(SetPayloadTransformationTarget.java:29)    at com.mulesoft.mule.runtime.core.internal.processor.TransformMessageProcessor.lambda$0(TransformMessageProcessor.java:87)    at java.util.Optional.ifPresent(Optional.java:159)    at com.mulesoft.mule.runtime.core.internal.processor.TransformMessageProcessor.process(TransformMessageProcessor.java:87)    at org.mule.runtime.core.api.processor.Processor.lambda$apply$0(Processor.java:55)    at org.mule.runtime.core.api.util.func.CheckedFunction.apply(CheckedFunction.java:19)    at org.mule.runtime.core.api.rx.Exceptions.lambda$checkedFunction$2(Exceptions.java:84)    at org.mule.runtime.core.internal.util.rx.Operators.lambda$nullSafeMap$0(Operators.java:45)    at reactor.core.publisher.FluxHandleFuseable$HandleFuseableSubscriber.onNext(FluxHandleFuseable.java:165)    at org.mule.runtime.core.privileged.processor.chain.AbstractMessageProcessorChain$1.onNext(AbstractMessageProcessorChain.java:292)    at org.mule.runtime.core.privileged.processor.chain.AbstractMessageProcessorChain$1.onNext(AbstractMessageProcessorChain.java:285)    at reactor.core.publisher.FluxHide$SuppressFuseableSubscriber.onNext(FluxHide.java:127)    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:204)    at reactor.core.publisher.FluxOnAssembly$OnAssemblySubscriber.onNext(FluxOnAssembly.java:345)    at reactor.core.publisher.FluxSubscribeOnValue$ScheduledScalar.run(FluxSubscribeOnValue.java:178)    at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:50)    at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:27)    at java.util.concurrent.FutureTask.run(FutureTask.java:266)    at org.mule.service.scheduler.internal.AbstractRunnableFutureDecorator.doRun(AbstractRunnableFutureDecorator.java:111)    at org.mule.service.scheduler.internal.RunnableFutureDecorator.run(RunnableFutureDecorator.java:54)    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)    at java.lang.Thread.run(Thread.java:748)********************************************************************************



Kindly guide what can be done.