How can I apply for an Education Visa at Chiang Mai University as an American citizen with permanent residency in Taiwan?

The eVisa system doesn't go live in Taiwan until Jan 1 and they only accept in person applications until Dec 27th

So if you want to apply for an ED visa get the documents sent to you by CMU, and go apply in person at that consulate BEFORE Dec 27th when they stop taking in person applications

OR

wait until they DO go online with the eVisa system Jan 1, 2025 and then apply online thru the eVisa portal.

You don't need PR status in Taiwian to use the consulate there,

It's just because TTEO is NOT yet on eVisa system. They will start on 1 Jan 2025. You will apply for a visa in person at that office if within this year. Check this post.

3/

you will see announcement about eVisa implementation there easily on their website.