You can use this code and add in wplms customizer plugin
add_filter('wplms_course_details_widget','wplms_information1',999);
function wplms_information1($details){
$details['number_units']['label']='chnage number of units text';
$details['number_sections']['label']='chnage number of sections text';
return $details;
}
Here, we are translating the string using custom code