How to make links permanent when using WT Geotargeting plugin?

Question

Can you tell me who used the WT Geotargeting plugin, how to implement links with cities like this:

site.com/kazan/

Now the links come with a get parameter and at the end the city in Cyrillic:

site.com/?wt_region_by_default=Казань

I tried to do as advised here, through the add_rewrite_tag but could not.