If your present job is part of what you are submitting as work experience, to gain you points for your ITA, you will have to give evidence of that. What the evidence is can vary from one person or job to another. It might be possible to show where you work and what the requirements, your responsibilities and your salary are by means of your contract or the original advertisement from which you got the job. But sooner or later, INZ will require to contact
someone for confirmation that the paperwork is genuine.