i want to add a link in a sublist of a suitelet like this: This is the header

sublist.addField({id: "custpage_transactionnumber", label: "Transaction Number", type:serverWidget.FieldType.URL });

and this is the sublist row

sublist.setSublistValue({id: "custpage_transactionnumber", line: 1, value: "http://…."}).linkTest = transaction.number

I get an error: cannot set property “linkText” of null is there any restriction of using fieldType URL in suitelet sublist? If so, is there any workaround to display links is sublist results? thanks