Medical certificate when sick

I work in a Bupa nursing home. When do I have to produce evidence of being sick from work?

Clause 35.5 of the Bupa Aged Care Australia, NSWNMA, ANMF (NSW Branch) and HSU NSW Branch, New South Wales Enterprise Agreement 2018 sets out that a medical certificate, or a statutory declaration, is required if the illness exceeds two consecutive working days. Note that differing requirements exist if the leave is in relation to carer’s responsibilities or family and domestic violence.