Quick note about ACX Check. It’s only the first test that ACX does to your submission. If that passes the basics, the work goes to ACX Human Quality Control where they find out that your voice is distorted and you can’t read out loud.
There is also a trick to preparing an ACX test.
https://forum.audacityteam.org/t/how-to-send-a-test-to-acx/49588/1
And you can submit a test here before you send them one.
http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html
Koz