Look at the link you posted
With American PetEmbark, we offer more than 65 years of expertise transporting animals and are committed to the welfare of every pet in our care.
www.aacargo.com
In the section titled
How to fly with your pet
There is a link to a list of things to check before calling them.
Getting your pets ready to fly takes a little legwork, but the information you provide helps us keep your pets safe and comfortable.
www.aacargo.com
First is age. Phoenix is over 8 weeks old so good there
Second is restricted breeds
Phoenix is not a flat nosed cat or dog such as a Himalayan or Pug etc so good here
Third is to verify there is a flight departing from and going to where you need with the right aircraft as some have the pet area some don't.
This is where we have a problem. There are no flights nonstop or indirect from PDX ( Portland Oregon Airport) to MIC ( Minneapolis St.Paul Airport). It's not that it's the wrong type of aircraft there are no flights at all.