About two years ago, I moved from Sydney to Toronto. My Working Holiday visa expires in the next month and I applied for an extension a few weeks ago. I called the IRCC today and they told me it's very unlikely that I will get an extension due to a note left on my file. They also told me that if it was denied for the extension that I would have to apply for a work visa specific to my qualifications and that would I would have to stay in that job. After two years in that position, I would be able to apply for Permanent Residency.
As of right now, Australians can only participate in the International Experience Class (IEC) Working Holiday category once. The government previously allowed unlimited participation for Australians who met the criteria of the class.
Given that you’ve reached your two years of participation, you will need to leave Canada so that you do not exceed your authorized stay. You will need to return to Canada as either a visitor (during which you cannot work), or after you’ve secured a new work permit, likely backed by a Labour Market Impact Assessment (LMIA).
International Experience Class (IEC) workers may also want to assess their eligibility for the Canadian Experience Class (CEC). Often those who have worked in Canada are eligible under this class of application, and do not need to pursue a second work permit.