Per the Herald, you can show proof through one of these options:
An official, government-issued vaccination card listing the guest’s name and dates of doses, including the date the last dose was administered.
A photo or digital version of an official, government-issued vaccination card listing the guest’s name and dates of doses, including the date the last dose was administered.
A printed or digital negative COVID-19 PCR or antigen test administered by a healthcare professional within 72 hours prior to a guest’s given event that includes the guest’s name and the date of the test.