[Решено] Question on setting up my WPML

Background of the issue:
I am trying to set up WPML on my main site, which already has existing multilingual URLs.

Symptoms:
When I click submit, these URLs are reported as invalid.

Questions:
Why are the existing multilingual URLs considered invalid when I try to set them up in WPML?
Can you assist me in correctly setting up these multilingual URLs in WPML?