REST snap errors when passing in variables for HTTP Entity and Service URL

I’m basically doing what is described in the following article but am getting an error.

Failure: Service URL: $serviceUrl is undefined. Perhaps you meant: $requestBody, Reason: ‘serviceUrl’ was not found while evaluating the sub-expression ‘$serviceUrl’, Resolution: Check the spelling of the property or, if the property is optional, use the get() method (e.g. $.get(‘serviceUrl’))

This is from my REST Patch snap:

This is the json that is the input for the REST Patch snap:

[

{

“requestBody”:

{

“ExternalIdentifierNumber”:

“002500012”

}

}

{

“serviceUrl”:

"https:///”

}

]

Thanks,
Scott