Since you won't post the code and the error message as I previously asked, we can only guess, but it seems that you are passing an AssociativeArray to AsyncPostFromString. It needs to be a string, not an AA, as you yourself said in your last post. An AA is not a string. This code should work. Note that the first line is necessary since "null" is not a reserved word in Brightscript, as RokuKC already told you earlier.
null = invalid
param={"abcd":{"isDevice":false,"soapRequest":{"contractAcceptanceMedium":"WEB"}},"searchCustomerProfileRestRequest":{"soapRequest":{"customerSearch":{"address":{"streetAddress1":"UgRnJhbmtsaW4gU3Q=","unitNumber":"NzY0Mg==","zipCode":"MjMyMTk="},"sessionId":""}}},"selectCustomerProfileRestRequest":{"soapRequest":{"sessionId":"","searchSelectionChoice":{}}},"queryBadDebtRestRequest":{"soapRequest":{"sessionId":"","firstName":null,"lastName":null,"emailAddress":null,"socialSecurityNumber":null,"telephoneNumber":null,"creditCheckConsent":false},"dateOfBirth":null}}
param_string = FormatJSON(param)
url.AsyncPostFromString(param_string)
If you are still having problems, please POST THE ERROR MESSAGE that you are seeing.
--Mark