Background of the issue:
I am in the process of moving our existing content to WordPress with WPML. We have inserted most of the content, including translations. Previously, the setting 'Translated documents options' -> 'Page URL' was set to 'Auto-generate'. I have now changed it to 'Translate'.
Symptoms:
For existing posts, the post's URL doesn't appear in the Advanced Translation Editor, so it cannot be translated.
Questions:
How can I translate the URL of existing pages after changing 'Translated documents options' -> 'Page URL' from 'Auto-generate' to 'Translate'?