Yes, you can change the url slug by searching for the custom post type where it is created i.e register_post_type and change the slug parameter value to whatever you like.You can follow the following steps..
Locate and replace post type slug with any slug you need, try not to use spaces.
1) Just search for slug you need to update.
The script should look like:
‘slug’ => ‘walk’
2) Save the file and test your website.
3) Sometimes you may get 404 error after changing custom post type slug, it is related to permalinks issue. You need to open admin panel, change permalinks structure to default, save website and then revert it to previous state.