condition editor in sap apim null empty and regular expression string validation

condition editor in api ,

(request.header.sourceType = "" or request.header.sourceType Is null )

 or ( request.header.source = "" or request.header.source Is null)

 or (request.header.stockBalanceDate Is null or request.header.stockBalanceDate="") or

 not(request.header.stockBalanceDate ~~ "^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}UTC[+-]\d{2}:\d{2}$")