I had a hard time to have a feedback from a Visual Force Page to a Lightning web component by using iframe and postMessage. Thus I am using Lightning Message Channel ( which is at Developer Preview stage) for my sandbox, however after creating the file of SampleMessageChannel.messageChannel-meta.xml, I could not deploy it to the sandbox and below is the error:
The link I used for creating this .xml file is Salesforce Lightning Message channel
Please advise if this error is due to my sandbox is not a Developer version and how to I make it becomes a Developer version to enable this feature in Sandbox and to deploy to Production using the changeset?. Thanks.