I had an Australia ETA and it expired since I visited Australia 2 months ago. Now I'm applying for a Taiwan Travel Authorization, using this ETA. They said "Upon arrival, the visitor is required to present the Travel Authorization Certificate together with the Australian visa". So how do I print out my Australian e-visa?
To be eligible for the ROC travel authorization, the Australian e-visa would have to be valid, as noted: yours has expired. You further asked whether the e-visa would be considered 'a resident card or visa that has expired less than 10 years prior to the date of arrival in Taiwan." That item points to long term permission to remain in a country, rather than the Electronic Travel Authority (ETA) you had, which is linked to short term stays for tourism or business.