Hello There,
Thanks for contacting WPML Support. Sorry for the delay in responding due to the weekend.
I understood what you're looking for. Please follow the steps mentioned below and I hope it will help.
1. Go to WPML → Settings. Scroll to "Translated documents options".
2. Under Page URL, choose the Translate option. Click Save.
[Check this documentation for a better understanding: https://wpml.org/documentation/getting-started-guide/translating-page-slugs/#sending-post-or-page-slugs-to-translators ]
3. After that, open the original post(post in the English language) in WordPress Editor and make a small change in the title(add any character) and save the changes.
4. Once you save the changes, you'll notice a translation update icon under the language meta section(screenshot: hidden link). Click on that icon.
5. On the Translation editor, you'll see the field to enter the slug for translated page or post. Add the slug as per your needs.
Please let me know if that helps or if you need further assistance. I will be happy to help.