The posters are downloadable and intended to be used by small businesses in shopfronts to communicate with their clients and customers. They have a space at the bottom to allow small businesses to customise them. Where you have capacity you might also consider printing and posting them to small businesses if needed.
https://www.health.gov.au/resources/collections/coronavirus-covid-19-campaign-resources
Department of Industry, Science, Energy and Resources | www.industry.gov.au