Hi there.
The answer to your question is here 👇
https://help.fiverr.com/hc/en-us/articles/29453001296913-How-to-become-a-Fiverr-Pro-freelancer
And from my experience, I am not a Fiverr pro seller, I had heard back to Fiverr Pro team after about a year of submitting my application, saying that they missed my application. That was 3 years ago. I don't know how it works now.