How to Change the Testimonials Slug

Add the following function to your theme’s functions.php file. Change the return value in the first function to whatever you want your page to be:

function change_testimonial_rotator_testimonial_slug( $name ) { return "praise"; }
add_filter( 'testimonial_rotator_testimonial_slug', 'change_testimonial_rotator_testimonial_slug' );

After you add this bit of code, you will need to go into ‘Settings’ -> ‘Permalinks’ and just resave that page. It will flush your url links and create new ones.