✔ 最佳答案
It is best to renew your Portuguese passport if you still can, because it is much simpler, cheaper(!!!) and can stay longer in Taiwan (30days) You just arrive and proceed straight to the immigration counter.
But if you insist on using your Macau SAR passport, you can either arrange to do it online or go for an On-Arrival Visa, since you said you born in Macau, you can apply for an arrival visa before the immigration counters in both Terminal 1 and 2 in Taoyuan (CKS) Airport.
You need the following:-
A completed arrival visa application form (obtainable next to the counter)
Macau SAR Passport
Macau SAR ID
NT$200!!! (No coins, no change and no foreign currencies, which means you'll need $100x2) (You can change money not far from that counter)
What you'll receive:
The "visa" (green paper) itself, which allows you to stay in Taiwan for 14 days (Check for accuracy!)
Receipt for $200 payment
You need to present
Passport, Visa, Departure/Arrival Form to the immigration official.
As for online visa, I think it's better than On Arrival visa, because you can enter Taiwan twice within 3 months and it costs the same (HK$50). The procedure is similar to the On Arrival method.
Happy Travel!