It’s in the documentation:
Displaying language variables for tooltips
It is possible to display all language variables for tooltips directly on the desired page. To display them, add the following parameters to the selected page URL: stt - to display tooltips and сtpl - to clear cache.
For example, to display all tooltips on the following page:
http://example.com/admin.php?dispatch=products.update&product_id=180
open the URL:
http://example.com/admin.php?dispatch=products.update&product_id=180&stt&ctpl
The pop-up boxes with two language variables will be displayed for each form field. If the variable value is already defined, it will be also displayed in the same pop-up box.
This doesn’t work in our installation or in the demo version:
https://demos.mv.cs-cart.com/8d3188305b46283d/admin.php?dispatch=products.update&product_id=5778&stt&ctpl
What is wrong here?